diff --git a/mozilla/caps/src/nsScriptSecurityManager.cpp b/mozilla/caps/src/nsScriptSecurityManager.cpp
index 2d1b52f0908..5043714341a 100644
--- a/mozilla/caps/src/nsScriptSecurityManager.cpp
+++ b/mozilla/caps/src/nsScriptSecurityManager.cpp
@@ -80,6 +80,7 @@
 #include "nsIObserverService.h"
 #include "nsIContent.h"
 #include "nsAutoPtr.h"
+#include "nsDOMJSUtils.h"
 
 static NS_DEFINE_CID(kZipReaderCID, NS_ZIPREADER_CID);
 
diff --git a/mozilla/content/base/src/nsGenericElement.cpp b/mozilla/content/base/src/nsGenericElement.cpp
index 27877994b49..985181e639c 100644
--- a/mozilla/content/base/src/nsGenericElement.cpp
+++ b/mozilla/content/base/src/nsGenericElement.cpp
@@ -3384,8 +3384,9 @@ nsGenericElement::AddScriptEventListener(nsIAtom* aAttribute,
   if (manager) {
     nsIDocument *ownerDoc = GetOwnerDoc();
 
+    PRUint32 lang = nsIProgrammingLanguage::JAVASCRIPT; // XXX - fix me!
     rv =
-      manager->AddScriptEventListener(target, aAttribute, aValue, defer,
+      manager->AddScriptEventListener(target, aAttribute, aValue, lang, defer,
                                       !nsContentUtils::IsChromeDoc(ownerDoc));
   }
 
diff --git a/mozilla/content/base/src/nsParserUtils.cpp b/mozilla/content/base/src/nsParserUtils.cpp
index 2d278225b1d..5dac3f6035e 100644
--- a/mozilla/content/base/src/nsParserUtils.cpp
+++ b/mozilla/content/base/src/nsParserUtils.cpp
@@ -40,6 +40,7 @@
 #include "jsapi.h"
 #include "nsReadableUtils.h"
 #include "nsCRT.h"
+#include "nsIProgrammingLanguage.h"
 
 #define SKIP_WHITESPACE(iter, end_iter)                          \
   while ((iter) != (end_iter) && nsCRT::IsAsciiSpace(*(iter))) { \
@@ -124,7 +125,7 @@ nsParserUtils::GetQuotedAttributeValue(const nsAString& aSource,
 // Returns PR_TRUE if the language name is a version of JavaScript and
 // PR_FALSE otherwise
 PRBool
-nsParserUtils::IsJavaScriptLanguage(const nsString& aName, const char* *aVersion)
+nsParserUtils::IsJavaScriptLanguage(const nsString& aName, PRUint32 *aFlags)
 {
   JSVersion version = JSVERSION_UNKNOWN;
 
@@ -153,7 +154,7 @@ nsParserUtils::IsJavaScriptLanguage(const nsString& aName, const char* *aVersion
   }
   if (version == JSVERSION_UNKNOWN)
     return PR_FALSE;
-  *aVersion = JS_VersionToString(version);
+  *aFlags = version;
   return PR_TRUE;
 }
 
diff --git a/mozilla/content/base/src/nsParserUtils.h b/mozilla/content/base/src/nsParserUtils.h
index 4f8228389c7..befee835b97 100644
--- a/mozilla/content/base/src/nsParserUtils.h
+++ b/mozilla/content/base/src/nsParserUtils.h
@@ -48,7 +48,7 @@ public:
                           nsAString& aValue);
 
   static PRBool
-  IsJavaScriptLanguage(const nsString& aName, const char* *aVersion);
+  IsJavaScriptLanguage(const nsString& aName, PRUint32 *aVerFlags);
 
   static void
   SplitMimeType(const nsAString& aValue, nsString& aType,
diff --git a/mozilla/content/base/src/nsScriptLoader.cpp b/mozilla/content/base/src/nsScriptLoader.cpp
index 322ae8fd760..7c46742570e 100644
--- a/mozilla/content/base/src/nsScriptLoader.cpp
+++ b/mozilla/content/base/src/nsScriptLoader.cpp
@@ -48,6 +48,7 @@
 #include "nsNetUtil.h"
 #include "nsIScriptGlobalObject.h"
 #include "nsIScriptContext.h"
+#include "nsILanguageRuntime.h"
 #include "nsINodeInfo.h"
 #include "nsIScriptSecurityManager.h"
 #include "nsIPrincipal.h"
@@ -63,6 +64,7 @@
 #include "nsAutoPtr.h"
 
 static NS_DEFINE_CID(kCharsetConverterManagerCID, NS_ICHARSETCONVERTERMANAGER_CID);
+static NS_DEFINE_CID(kDOMScriptObjectFactoryCID, NS_DOM_SCRIPT_OBJECT_FACTORY_CID);
 
 //////////////////////////////////////////////////////////////
 //
@@ -108,8 +110,7 @@ class nsScriptLoadRequest : public nsISupports {
 public:
   nsScriptLoadRequest(nsIScriptElement* aElement,
                       nsIScriptLoaderObserver* aObserver,
-                      const char* aVersionString,
-                      PRBool aHasE4XOption);
+                      PRUint32 aVersion);
   virtual ~nsScriptLoadRequest();
 
   NS_DECL_ISUPPORTS
@@ -123,21 +124,19 @@ public:
   PRPackedBool mLoading;             // Are we still waiting for a load to complete?
   PRPackedBool mWasPending;          // Processed immediately or pending
   PRPackedBool mIsInline;            // Is the script inline or loaded?
-  PRPackedBool mHasE4XOption;        // Has E4X=1 script type parameter
   nsString mScriptText;              // Holds script for loaded scripts
-  const char* mJSVersion;            // We don't own this string
+  PRUint32 mJSVersion;
   nsCOMPtr<nsIURI> mURI;
   PRInt32 mLineNo;
 };
 
 nsScriptLoadRequest::nsScriptLoadRequest(nsIScriptElement* aElement,
                                          nsIScriptLoaderObserver* aObserver,
-                                         const char* aVersionString,
-                                         PRBool aHasE4XOption) :
+                                         PRUint32 aVersion) :
   mElement(aElement), mObserver(aObserver),
   mLoading(PR_TRUE), mWasPending(PR_FALSE),
-  mIsInline(PR_TRUE), mHasE4XOption(aHasE4XOption),
-  mJSVersion(aVersionString), mLineNo(1)
+  mIsInline(PR_TRUE),
+  mJSVersion(aVersion), mLineNo(1)
 {
 }
 
@@ -380,6 +379,8 @@ nsScriptLoader::ProcessScriptElement(nsIScriptElement *aElement,
 
   // Script evaluation can also be disabled in the current script
   // context even though it's enabled in the document.
+  // XXXMarkh - note we are still checking js here even though another
+  // language may be specified.  Need to clarify the "IsEnabled()" semantics
   nsIScriptGlobalObject *globalObject = mDocument->GetScriptGlobalObject();
   if (globalObject)
   {
@@ -393,35 +394,20 @@ nsScriptLoader::ProcessScriptElement(nsIScriptElement *aElement,
     }
   }
 
-  PRBool isJavaScript = PR_TRUE;
-  PRBool hasE4XOption = PR_FALSE;
-  const char* jsVersionString = nsnull;
+  nsCOMPtr<nsIDOMScriptObjectFactory> factory = do_GetService(kDOMScriptObjectFactoryCID);
+  NS_ENSURE_TRUE(factory, nsnull);
+  
+  nsCOMPtr<nsILanguageRuntime> languageRuntime;
+  PRUint32 version = 0;
+  PRBool seenLanguage = PR_FALSE;
+
   nsAutoString language, type, src;
 
-  // "language" is a deprecated attribute of HTML, so we check it only for
-  // HTML script elements.
-  nsCOMPtr<nsIDOMHTMLScriptElement> htmlScriptElement =
-    do_QueryInterface(aElement);
-  if (htmlScriptElement) {
-    // Check the language attribute first, so type can trump language.
-    htmlScriptElement->GetAttribute(NS_LITERAL_STRING("language"), language);
-    if (!language.IsEmpty()) {
-      isJavaScript = nsParserUtils::IsJavaScriptLanguage(language,
-                                                         &jsVersionString);
-
-      // IE, Opera, etc. do not respect language version, so neither should
-      // we at this late date in the browser wars saga.  Note that this change
-      // affects HTML but not XUL or SVG (but note also that XUL has its own
-      // code to check nsParserUtils::IsJavaScriptLanguage -- that's probably
-      // a separate bug, one we may not be able to fix short of XUL2).  See
-      // bug 255895 (https://bugzilla.mozilla.org/show_bug.cgi?id=255895).
-      jsVersionString = ::JS_VersionToString(JSVERSION_DEFAULT);
-    }
-  }
-
   // Check the type attribute to determine language and version.
+  // If type exists, it trumps the deprecated 'language='
   aElement->GetScriptType(type);
   if (!type.IsEmpty()) {
+    seenLanguage = PR_TRUE;
     nsCOMPtr<nsIMIMEHeaderParam> mimeHdrParser =
       do_GetService("@mozilla.org/network/mime-hdrparam;1");
     NS_ENSURE_TRUE(mimeHdrParser, NS_ERROR_FAILURE);
@@ -434,6 +420,7 @@ nsScriptLoader::ProcessScriptElement(nsIScriptElement *aElement,
                                      mimeType);
     NS_ENSURE_SUCCESS(rv, rv);
 
+    // Javascript keeps the fast path, optimized for most-likely type
     // Table ordered from most to least likely JS MIME types.
     // See bug 62485, feel free to add <script type="..."> survey data to it,
     // or to a new bug once 62485 is closed.
@@ -446,37 +433,44 @@ nsScriptLoader::ProcessScriptElement(nsIScriptElement *aElement,
       nsnull
     };
 
-    isJavaScript = PR_FALSE;
+    PRBool isJavaScript = PR_FALSE;
     for (PRInt32 i = 0; jsTypes[i]; i++) {
       if (mimeType.LowerCaseEqualsASCII(jsTypes[i])) {
         isJavaScript = PR_TRUE;
         break;
       }
     }
+    if (isJavaScript)
+      rv = factory->GetLanguageRuntimeByID(nsIProgrammingLanguage::JAVASCRIPT,
+                                           getter_AddRefs(languageRuntime));
+    else
+      // Use the object factory to locate a matching language.
+      rv = factory->GetLanguageRuntime(mimeType, getter_AddRefs(languageRuntime));
+    if (NS_FAILED(rv) || languageRuntime == nsnull) {
+      NS_WARNING("Failed to find a scripting language");
+      return NS_FAILED(rv) ? rv : NS_ERROR_UNEXPECTED;
+    }
 
-    if (isJavaScript) {
-      JSVersion jsVersion = JSVERSION_DEFAULT;
-      nsAutoString value;
-      rv = mimeHdrParser->GetParameter(typeAndParams, "version",
-                                       EmptyCString(), PR_FALSE, nsnull,
-                                       value);
+    // Get the version string, and ensure the language supports it.
+    nsAutoString versionName;
+    rv = mimeHdrParser->GetParameter(typeAndParams, "version",
+                                     EmptyCString(), PR_FALSE, nsnull,
+                                     versionName);
+    if (NS_FAILED(rv)) {
+      // no language specified - verion remains 0.
+      if (rv != NS_ERROR_INVALID_ARG)
+        return rv;
+    } else {
+      rv = languageRuntime->ParseVersion(versionName, &version);
       if (NS_FAILED(rv)) {
-        if (rv != NS_ERROR_INVALID_ARG)
-          return rv;
-      } else {
-        if (value.Length() != 3 || value[0] != '1' || value[1] != '.')
-          jsVersion = JSVERSION_UNKNOWN;
-        else switch (value[2]) {
-          case '0': jsVersion = JSVERSION_1_0; break;
-          case '1': jsVersion = JSVERSION_1_1; break;
-          case '2': jsVersion = JSVERSION_1_2; break;
-          case '3': jsVersion = JSVERSION_1_3; break;
-          case '4': jsVersion = JSVERSION_1_4; break;
-          case '5': jsVersion = JSVERSION_1_5; break;
-          default:  jsVersion = JSVERSION_UNKNOWN;
-        }
+        NS_WARNING("This script language version is not supported - ignored");
+        return rv;
       }
-      jsVersionString = ::JS_VersionToString(jsVersion);
+    }
+
+    // Some js specifics yet to be abstracted.
+    if (languageRuntime->GetLanguage() == nsIProgrammingLanguage::JAVASCRIPT) {
+      nsAutoString value;
 
       rv = mimeHdrParser->GetParameter(typeAndParams, "e4x",
                                        EmptyCString(), PR_FALSE, nsnull,
@@ -486,20 +480,59 @@ nsScriptLoader::ProcessScriptElement(nsIScriptElement *aElement,
           return rv;
       } else {
         if (value.Length() == 1 && value[0] == '1')
-          hasE4XOption = PR_TRUE;
+          version |= JSOPTION_XML;
+      }
+    }
+  } else {
+    // no 'type=' element
+    // "language" is a deprecated attribute of HTML, so we check it only for
+    // HTML script elements.
+    nsCOMPtr<nsIDOMHTMLScriptElement> htmlScriptElement =
+      do_QueryInterface(aElement);
+    if (htmlScriptElement) {
+      htmlScriptElement->GetAttribute(NS_LITERAL_STRING("language"), language);
+      if (!language.IsEmpty()) {
+        seenLanguage = PR_TRUE;
+        if (nsParserUtils::IsJavaScriptLanguage(language, &version)) {
+          rv = factory->GetLanguageRuntimeByID(nsIProgrammingLanguage::JAVASCRIPT,
+                                               getter_AddRefs(languageRuntime));
+          if (NS_FAILED(rv)) {
+            NS_ERROR("Failed to get javascript language");
+            return rv;
+          }
+        }
+        // IE, Opera, etc. do not respect language version, so neither should
+        // we at this late date in the browser wars saga.  Note that this change
+        // affects HTML but not XUL or SVG (but note also that XUL has its own
+        // code to check nsParserUtils::IsJavaScriptLanguage -- that's probably
+        // a separate bug, one we may not be able to fix short of XUL2).  See
+        // bug 255895 (https://bugzilla.mozilla.org/show_bug.cgi?id=255895).
+        NS_ASSERTION(JSVERSION_DEFAULT == 0,
+                     "We rely on all languages having 0 as a version default");
+        version = 0;
       }
     }
   }
 
-  // If this isn't JavaScript, we don't know how to evaluate.
-  // XXX How and where should we deal with other scripting languages?
-  //     See bug 255942 (https://bugzilla.mozilla.org/show_bug.cgi?id=255942).
-  if (!isJavaScript) {
+  if (!seenLanguage) {
+    NS_ASSERTION(languageRuntime == nsnull, "eh?");
+    rv = factory->GetLanguageRuntimeByID(nsIProgrammingLanguage::JAVASCRIPT,
+                                         getter_AddRefs(languageRuntime));
+    NS_ASSERTION(!NS_FAILED(rv), "Failed to get default JavaScript language!");
+  }
+
+  // If we don't know the language, we don't know how to evaluate
+  if (!languageRuntime) {
+    return FireErrorNotification(NS_ERROR_NOT_AVAILABLE, aElement, aObserver);
+  }
+  // Our nsScriptLoadRequest is not yet language agnostic
+  if (languageRuntime->GetLanguage() != nsIProgrammingLanguage::JAVASCRIPT) {
+    NS_WARNING("Nearly got another language executed");
     return FireErrorNotification(NS_ERROR_NOT_AVAILABLE, aElement, aObserver);
   }
 
   // Create a request object for this script
-  nsRefPtr<nsScriptLoadRequest> request = new nsScriptLoadRequest(aElement, aObserver, jsVersionString, hasE4XOption);
+  nsRefPtr<nsScriptLoadRequest> request = new nsScriptLoadRequest(aElement, aObserver, version);
   if (!request) {
     return FireErrorNotification(NS_ERROR_OUT_OF_MEMORY, aElement, aObserver);
   }
@@ -738,29 +771,19 @@ nsScriptLoader::EvaluateScript(nsScriptLoadRequest* aRequest,
   PRBool oldProcessingScriptTag = context->GetProcessingScriptTag();
   context->SetProcessingScriptTag(PR_TRUE);
 
-  JSContext *cx = (JSContext *)context->GetNativeContext();
-  uint32 options = ::JS_GetOptions(cx);
-  PRBool needE4X = aRequest->mHasE4XOption && !(options & JSOPTION_XML);
-  if (needE4X) {
-    ::JS_SetOptions(cx, options | JSOPTION_XML);
-  }
-
   // Update our current script.
   nsCOMPtr<nsIScriptElement> oldCurrent = mCurrentScript;
   mCurrentScript = aRequest->mElement;
 
   PRBool isUndefined;
-  context->EvaluateString(aScript, globalObject->GetGlobalJSObject(),
+  context->EvaluateString(aScript, globalObject->GetLanguageGlobal(nsIProgrammingLanguage::JAVASCRIPT),
                           principal, url.get(), aRequest->mLineNo,
                           aRequest->mJSVersion, nsnull, &isUndefined);
 
   // Put the old script back in case it wants to do anything else.
   mCurrentScript = oldCurrent;
 
-  ::JS_ReportPendingException(cx);
-  if (needE4X) {
-    ::JS_SetOptions(cx, options);
-  }
+  ::JS_ReportPendingException((JSContext *)context->GetNativeContext());
 
   context->SetProcessingScriptTag(oldProcessingScriptTag);
 
diff --git a/mozilla/content/events/public/nsIEventListenerManager.h b/mozilla/content/events/public/nsIEventListenerManager.h
index 3a029bfd3e7..b58912c1dcc 100644
--- a/mozilla/content/events/public/nsIEventListenerManager.h
+++ b/mozilla/content/events/public/nsIEventListenerManager.h
@@ -48,7 +48,9 @@ class nsIScriptContext;
 class nsIDOMEventTarget;
 class nsIDOMEventGroup;
 class nsIAtom;
-struct JSObject;
+
+class nsIScriptGlobalObject;
+class nsIScriptBinding;
 
 /*
  * Event listener manager interface.
@@ -102,6 +104,7 @@ public:
   NS_IMETHOD AddScriptEventListener(nsISupports *aObject,
                                     nsIAtom *aName,
                                     const nsAString& aFunc,
+                                    PRUint32 aLanguage,
                                     PRBool aDeferCompilation,
                                     PRBool aPermitUntrustedEvents) = 0;
 
@@ -116,7 +119,7 @@ public:
   * @param the name of an event listener
   */
   NS_IMETHOD RegisterScriptEventListener(nsIScriptContext *aContext,
-                                         JSObject *aScopeObject,
+                                         nsIScriptGlobalObject *aScopeGlobal,
                                          nsISupports *aObject,
                                          nsIAtom* aName) = 0;
 
@@ -125,8 +128,8 @@ public:
   * script object for a given event type.
   * @param an event listener */
   NS_IMETHOD CompileScriptEventListener(nsIScriptContext *aContext,
-                                        JSObject *aScopeObject,
-                                        nsISupports *aObject,
+                                        nsIScriptGlobalObject *aScopeObject,
+                                        nsIScriptBinding *aBinding,
                                         nsIAtom* aName,
                                         PRBool *aDidCompile) = 0;
 
diff --git a/mozilla/content/events/src/nsEventListenerManager.cpp b/mozilla/content/events/src/nsEventListenerManager.cpp
index 505110ee47d..e791f5c3999 100644
--- a/mozilla/content/events/src/nsEventListenerManager.cpp
+++ b/mozilla/content/events/src/nsEventListenerManager.cpp
@@ -103,6 +103,7 @@
 #include "nsIWidget.h"
 #include "nsContentUtils.h"
 #include "nsJSUtils.h"
+#include "nsDOMJSUtils.h"
 #include "nsIDOMEventGroup.h"
 #include "nsContentCID.h"
 
@@ -1176,8 +1177,8 @@ nsEventListenerManager::FindJSEventListener(EventArrayType aType)
 
 nsresult
 nsEventListenerManager::SetJSEventListener(nsIScriptContext *aContext,
-                                           JSObject *aScopeObject,
-                                           nsISupports *aObject,
+                                           nsIScriptGlobalObject *aScopeGlobal,
+                                           nsIScriptBinding *aBinding,
                                            nsIAtom* aName,
                                            PRBool aIsString,
                                            PRBool aPermitUntrustedEvents)
@@ -1196,7 +1197,7 @@ nsEventListenerManager::SetJSEventListener(nsIScriptContext *aContext,
     // If we didn't find a script listener or no listeners existed
     // create and add a new one.
     nsCOMPtr<nsIDOMEventListener> scriptListener;
-    rv = NS_NewJSEventListener(aContext, aScopeObject, aObject,
+    rv = NS_NewJSEventListener(aContext, aScopeGlobal, aBinding,
                                getter_AddRefs(scriptListener));
     if (NS_SUCCEEDED(rv)) {
       AddEventListener(scriptListener, arrayType, NS_EVENT_BITS_NONE, nsnull,
@@ -1230,32 +1231,28 @@ NS_IMETHODIMP
 nsEventListenerManager::AddScriptEventListener(nsISupports *aObject,
                                                nsIAtom *aName,
                                                const nsAString& aBody,
+                                               PRUint32 aLanguage,
                                                PRBool aDeferCompilation,
                                                PRBool aPermitUntrustedEvents)
 {
   nsIScriptContext *context = nsnull;
-  JSContext* cx = nsnull;
 
   nsCOMPtr<nsIContent> content(do_QueryInterface(aObject));
 
   nsCOMPtr<nsIDocument> doc;
 
   nsISupports *objiSupp = aObject;
-
-  JSObject *scope = nsnull;
+  nsCOMPtr<nsIScriptGlobalObject> global;
 
   if (content) {
     // Try to get context from doc
     doc = content->GetOwnerDoc();
-    nsIScriptGlobalObject *global;
 
     if (doc && (global = doc->GetScriptGlobalObject())) {
-      context = global->GetContext();
-      scope = global->GetGlobalJSObject();
+      context = global->GetLanguageContext(aLanguage);
     }
   } else {
     nsCOMPtr<nsPIDOMWindow> win(do_QueryInterface(aObject));
-    nsCOMPtr<nsIScriptGlobalObject> global;
     if (win) {
       NS_ASSERTION(win->IsInnerWindow(),
                    "Event listener added to outer window!");
@@ -1274,12 +1271,15 @@ nsEventListenerManager::AddScriptEventListener(nsISupports *aObject,
       }
     }
     if (global) {
-      context = global->GetContext();
-      scope = global->GetGlobalJSObject();
+      context = global->GetLanguageContext(aLanguage);
     }
   }
 
-  if (!context) {
+  if (context == nsnull) {
+    NS_ASSERTION(aLanguage == nsIProgrammingLanguage::JAVASCRIPT,
+                 "Need a multi-language stack?!?!?");
+    // OTOH, maybe using JS will do here - all we need is the global.
+    JSContext* cx = nsnull;
     // Get JSContext from stack, or use the safe context (and hidden
     // window global) if no JS is running.
     nsCOMPtr<nsIThreadJSContextStack> stack =
@@ -1295,8 +1295,9 @@ nsEventListenerManager::AddScriptEventListener(nsISupports *aObject,
     context = nsJSUtils::GetDynamicScriptContext(cx);
     NS_ENSURE_TRUE(context, NS_ERROR_FAILURE);
 
-    scope = ::JS_GetGlobalObject(cx);
-  } else if (!scope) {
+    global = context->GetGlobalObject();
+  }
+  if (!global) {
     NS_ERROR("Context reachable, but no scope reachable in "
              "AddScriptEventListener()!");
 
@@ -1305,27 +1306,22 @@ nsEventListenerManager::AddScriptEventListener(nsISupports *aObject,
 
   nsresult rv;
 
+  nsCOMPtr<nsIScriptBinding> binding;
+  void *scope = global->GetLanguageGlobal(context->GetLanguage());
+  rv = context->GetScriptBinding(aObject, scope, getter_AddRefs(binding));
+  NS_ENSURE_SUCCESS(rv, rv);
+
   if (!aDeferCompilation) {
-    JSContext *cx = (JSContext *)context->GetNativeContext();
-
-    nsCOMPtr<nsIXPConnectJSObjectHolder> holder;
-    rv = nsContentUtils::XPConnect()->WrapNative(cx, scope, aObject,
-                                                 NS_GET_IID(nsISupports),
-                                                 getter_AddRefs(holder));
-    NS_ENSURE_SUCCESS(rv, rv);
-
     // Since JSEventListeners only have a raw nsISupports pointer, it's
     // important that it point to the same object that the WrappedNative wraps.
     // (In the case of a tearoff, the tearoff will not persist).
-    nsCOMPtr<nsIXPConnectWrappedNative> wrapper = do_QueryInterface(holder);
-    NS_ASSERTION(wrapper, "wrapper must impl nsIXPConnectWrappedNative");
+    // XXXMarkh - JSEventListeners now hold a reference to the binding, which
+    // hold a reference to a nsIXPConnectJSObjectHolder - is this still a
+    // concern?  If so it need reinstating.
+    //nsCOMPtr<nsIXPConnectWrappedNative> wrapper = do_QueryInterface(holder);
+    //NS_ASSERTION(wrapper, "wrapper must impl nsIXPConnectWrappedNative");
 
-    objiSupp = wrapper->Native();
-
-    JSObject *scriptObject = nsnull;
-
-    rv = holder->GetJSObject(&scriptObject);
-    NS_ENSURE_SUCCESS(rv, rv);
+    // objiSupp = wrapper->Native();
 
     nsCOMPtr<nsIScriptEventHandlerOwner> handlerOwner =
       do_QueryInterface(aObject);
@@ -1336,7 +1332,7 @@ nsEventListenerManager::AddScriptEventListener(nsISupports *aObject,
     if (handlerOwner) {
       rv = handlerOwner->GetCompiledEventHandler(aName, &handler);
       if (NS_SUCCEEDED(rv) && handler) {
-        rv = context->BindCompiledEventHandler(scriptObject, aName, handler);
+        rv = context->BindCompiledEventHandler(binding, aName, handler);
         if (NS_FAILED(rv))
           return rv;
         done = PR_TRUE;
@@ -1357,7 +1353,7 @@ nsEventListenerManager::AddScriptEventListener(nsISupports *aObject,
       if (handlerOwner) {
         // Always let the handler owner compile the event handler, as
         // it may want to use a special context or scope object.
-        rv = handlerOwner->CompileEventHandler(context, scriptObject, aName,
+        rv = handlerOwner->CompileEventHandler(context, binding, aName,
                                                aBody, url.get(), lineNo, &handler);
       }
       else {
@@ -1371,7 +1367,7 @@ nsEventListenerManager::AddScriptEventListener(nsISupports *aObject,
         }
         const char *eventName = nsContentUtils::GetEventArgName(nameSpace);
 
-        rv = context->CompileEventHandler(scriptObject, aName, eventName,
+        rv = context->CompileEventHandler(binding, aName, eventName,
                                           aBody,
                                           url.get(), lineNo,
                                           (handlerOwner != nsnull),
@@ -1381,7 +1377,7 @@ nsEventListenerManager::AddScriptEventListener(nsISupports *aObject,
     }
   }
 
-  return SetJSEventListener(context, scope, objiSupp, aName, aDeferCompilation,
+  return SetJSEventListener(context, global, binding, aName, aDeferCompilation,
                             aPermitUntrustedEvents);
 }
 
@@ -1419,7 +1415,7 @@ nsEventListenerManager::sAddListenerID = JSVAL_VOID;
 
 NS_IMETHODIMP
 nsEventListenerManager::RegisterScriptEventListener(nsIScriptContext *aContext,
-                                                    JSObject *aScopeObject,
+                                                    nsIScriptGlobalObject *aScopeGlobal,
                                                     nsISupports *aObject, 
                                                     nsIAtom *aName)
 {
@@ -1438,24 +1434,18 @@ nsEventListenerManager::RegisterScriptEventListener(nsIScriptContext *aContext,
   if (NS_FAILED(rv = stack->Peek(&cx)))
     return rv;
 
-  JSContext *current_cx = (JSContext *)aContext->GetNativeContext();
-
-  nsCOMPtr<nsIXPConnectJSObjectHolder> holder;
-  rv = nsContentUtils::XPConnect()->
-    WrapNative(current_cx, aScopeObject, aObject, NS_GET_IID(nsISupports),
-               getter_AddRefs(holder));
+  nsCOMPtr<nsIScriptBinding> scriptBinding;
+  void *scope = aScopeGlobal->GetLanguageGlobal(aContext->GetLanguage());
+  rv = aContext->GetScriptBinding(aObject, scope, getter_AddRefs(scriptBinding));
   NS_ENSURE_SUCCESS(rv, rv);
-
+  
   // Since JSEventListeners only have a raw nsISupports pointer, it's
   // important that it point to the same object that the WrappedNative wraps.
   // (In the case of a tearoff, the tearoff will not persist).
-  nsCOMPtr<nsIXPConnectWrappedNative> wrapper = do_QueryInterface(holder);
-  NS_ASSERTION(wrapper, "wrapper must impl nsIXPConnectWrappedNative");
+  // XXX - eeek!  Is this ok?
+  // nsCOMPtr<nsIXPConnectWrappedNative> wrapper = do_QueryInterface(holder);
+  // NS_ASSERTION(wrapper, "wrapper must impl nsIXPConnectWrappedNative");
 
-  JSObject *jsobj = nsnull;
-
-  rv = holder->GetJSObject(&jsobj);
-  NS_ENSURE_SUCCESS(rv, rv);
 
   if (cx) {
     if (sAddListenerID == JSVAL_VOID) {
@@ -1463,27 +1453,32 @@ nsEventListenerManager::RegisterScriptEventListener(nsIScriptContext *aContext,
         STRING_TO_JSVAL(::JS_InternString(cx, "addEventListener"));
     }
 
-    rv = nsContentUtils::GetSecurityManager()->
-      CheckPropertyAccess(cx, jsobj,
-                          "EventTarget",
-                          sAddListenerID,
-                          nsIXPCSecurityManager::ACCESS_SET_PROPERTY);
-    if (NS_FAILED(rv)) {
-      // XXX set pending exception on the native call context?
-      return rv;
+    if (scriptBinding->GetLanguage() == nsIProgrammingLanguage::JAVASCRIPT) {
+        rv = nsContentUtils::GetSecurityManager()->
+          CheckPropertyAccess(cx, (JSObject *)scriptBinding->GetNativeObject(),
+                              "EventTarget",
+                              sAddListenerID,
+                              nsIXPCSecurityManager::ACCESS_SET_PROPERTY);
+        if (NS_FAILED(rv)) {
+          // XXX set pending exception on the native call context?
+          return rv;
+        }
+    } else {
+        NS_WARNING("Skipping CheckPropertyAccess for non JS language");
     }
+        
   }
 
   // Untrusted events are always permitted for non-chrome script
   // handlers.
-  return SetJSEventListener(aContext, aScopeObject, wrapper->Native(), aName,
+  return SetJSEventListener(aContext, aScopeGlobal, scriptBinding, aName,
                             PR_FALSE, !nsContentUtils::IsCallerChrome());
 }
 
 nsresult
 nsEventListenerManager::CompileScriptEventListener(nsIScriptContext *aContext, 
-                                                   JSObject *aScopeObject,
-                                                   nsISupports *aObject, 
+                                                   nsIScriptGlobalObject *aScopeGlobal,
+                                                   nsIScriptBinding *aBinding, 
                                                    nsIAtom *aName,
                                                    PRBool *aDidCompile)
 {
@@ -1505,7 +1500,7 @@ nsEventListenerManager::CompileScriptEventListener(nsIScriptContext *aContext,
   }
 
   if (ls->mHandlerIsString & subType) {
-    rv = CompileEventHandlerInternal(aContext, aScopeObject, aObject, aName,
+    rv = CompileEventHandlerInternal(aContext, aScopeGlobal, aBinding, aName,
                                      ls, /*XXX fixme*/nsnull, subType);
   }
 
@@ -1521,8 +1516,8 @@ nsEventListenerManager::CompileScriptEventListener(nsIScriptContext *aContext,
 
 nsresult
 nsEventListenerManager::CompileEventHandlerInternal(nsIScriptContext *aContext,
-                                                    JSObject *aScopeObject,
-                                                    nsISupports *aObject,
+                                                    nsIScriptGlobalObject *aScopeGlobal,
+                                                    nsIScriptBinding *aBinding,
                                                     nsIAtom *aName,
                                                     nsListenerStruct *aListenerStruct,
                                                     nsIDOMEventTarget* aCurrentTarget,
@@ -1530,27 +1525,14 @@ nsEventListenerManager::CompileEventHandlerInternal(nsIScriptContext *aContext,
 {
   nsresult result = NS_OK;
 
-  JSContext *cx = (JSContext *)aContext->GetNativeContext();
-
-  nsCOMPtr<nsIXPConnectJSObjectHolder> holder;
-  result = nsContentUtils::XPConnect()->WrapNative(cx, aScopeObject, aObject,
-                                                   NS_GET_IID(nsISupports),
-                                                   getter_AddRefs(holder));
-  NS_ENSURE_SUCCESS(result, result);
-
-  JSObject *jsobj = nsnull;
-
-  result = holder->GetJSObject(&jsobj);
-  NS_ENSURE_SUCCESS(result, result);
-
   nsCOMPtr<nsIScriptEventHandlerOwner> handlerOwner =
-    do_QueryInterface(aObject);
+    do_QueryInterface(aBinding->GetTarget());
   void* handler = nsnull;
 
   if (handlerOwner) {
     result = handlerOwner->GetCompiledEventHandler(aName, &handler);
     if (NS_SUCCEEDED(result) && handler) {
-      result = aContext->BindCompiledEventHandler(jsobj, aName, handler);
+      result = aContext->BindCompiledEventHandler(aBinding, aName, handler);
       aListenerStruct->mHandlerIsString &= ~aSubType;
     }
   }
@@ -1560,7 +1542,7 @@ nsEventListenerManager::CompileEventHandlerInternal(nsIScriptContext *aContext,
     // XXX I don't like that we have to reference content
     // from here. The alternative is to store the event handler
     // string on the JS object itself.
-    nsCOMPtr<nsIContent> content = do_QueryInterface(aObject);
+    nsCOMPtr<nsIContent> content = do_QueryInterface(aBinding->GetTarget());
     NS_ASSERTION(content, "only content should have event handler attributes");
     if (content) {
       nsAutoString handlerBody;
@@ -1605,7 +1587,7 @@ nsEventListenerManager::CompileEventHandlerInternal(nsIScriptContext *aContext,
           // Always let the handler owner compile the event
           // handler, as it may want to use a special
           // context or scope object.
-          result = handlerOwner->CompileEventHandler(aContext, jsobj, aName,
+          result = handlerOwner->CompileEventHandler(aContext, aBinding, aName,
                                                      handlerBody,
                                                      url.get(), lineNo,
                                                      &handler);
@@ -1614,7 +1596,7 @@ nsEventListenerManager::CompileEventHandlerInternal(nsIScriptContext *aContext,
           const char *eventName =
             nsContentUtils::GetEventArgName(content->GetNameSpaceID());
 
-          result = aContext->CompileEventHandler(jsobj, aName, eventName,
+          result = aContext->CompileEventHandler(aBinding, aName, eventName,
                                                  handlerBody,
                                                  url.get(), lineNo,
                                                  (handlerOwner != nsnull),
@@ -1665,8 +1647,8 @@ nsEventListenerManager::HandleEventSubType(nsListenerStruct* aListenerStruct,
           nsCOMPtr<nsIAtom> atom = do_GetAtom(NS_LITERAL_STRING("on") + eventString);
 
           result = CompileEventHandlerInternal(jslistener->GetEventContext(),
-                                               jslistener->GetEventScope(),
-                                               jslistener->GetEventTarget(),
+                                               jslistener->GetEventGlobal(),
+                                               jslistener->GetEventBinding(),
                                                atom, aListenerStruct,
                                                aCurrentTarget,
                                                aSubType);
diff --git a/mozilla/content/events/src/nsEventListenerManager.h b/mozilla/content/events/src/nsEventListenerManager.h
index 485eb9bab33..6b8ba92aae1 100644
--- a/mozilla/content/events/src/nsEventListenerManager.h
+++ b/mozilla/content/events/src/nsEventListenerManager.h
@@ -131,16 +131,17 @@ public:
   NS_IMETHOD AddScriptEventListener(nsISupports *aObject,
                                     nsIAtom *aName,
                                     const nsAString& aFunc,
+                                    PRUint32 aLanguage,
                                     PRBool aDeferCompilation,
                                     PRBool aPermitUntrustedEvents);
   NS_IMETHOD RegisterScriptEventListener(nsIScriptContext *aContext,
-                                         JSObject *aScopeObject,
+                                         nsIScriptGlobalObject *aScopeObject,
                                          nsISupports *aObject,
                                          nsIAtom* aName);
   NS_IMETHOD RemoveScriptEventListener(nsIAtom *aName);
   NS_IMETHOD CompileScriptEventListener(nsIScriptContext *aContext,
-                                        JSObject *aScopeObject,
-                                        nsISupports *aObject,
+                                        nsIScriptGlobalObject *aScopeObject,
+                                        nsIScriptBinding *aBinding,
                                         nsIAtom* aName, PRBool *aDidCompile);
 
   NS_IMETHOD CaptureEvent(PRInt32 aEventTypes);
@@ -201,15 +202,15 @@ protected:
                               PRUint32 aSubType,
                               PRUint32 aPhaseFlags);
   nsresult CompileEventHandlerInternal(nsIScriptContext *aContext,
-                                       JSObject *aScopeObject,
-                                       nsISupports *aObject,
+                                       nsIScriptGlobalObject *aScopeObject,
+                                       nsIScriptBinding *aBinding,
                                        nsIAtom *aName,
                                        nsListenerStruct *aListenerStruct,
                                        nsIDOMEventTarget* aCurrentTarget,
                                        PRUint32 aSubType);
   nsListenerStruct* FindJSEventListener(EventArrayType aType);
   nsresult SetJSEventListener(nsIScriptContext *aContext,
-                              JSObject *aScopeObject, nsISupports *aObject,
+                              nsIScriptGlobalObject *aScopeGlobal, nsIScriptBinding *aObject,
                               nsIAtom* aName, PRBool aIsString,
                               PRBool aPermitUntrustedEvents);
   nsresult AddEventListener(nsIDOMEventListener *aListener, 
diff --git a/mozilla/content/html/content/src/nsHTMLScriptElement.cpp b/mozilla/content/html/content/src/nsHTMLScriptElement.cpp
index 173b6ffb043..1d8e0e63079 100644
--- a/mozilla/content/html/content/src/nsHTMLScriptElement.cpp
+++ b/mozilla/content/html/content/src/nsHTMLScriptElement.cpp
@@ -57,7 +57,7 @@
 #include "nsServiceManagerUtils.h"
 #include "nsIScriptEventHandler.h"
 #include "nsIDOMDocument.h"
-
+#include "nsIArray.h"
 
 //
 // Helper class used to support <SCRIPT FOR=object EVENT=handler ...>
@@ -224,23 +224,11 @@ nsHTMLScriptEventHandler::Invoke(nsISupports *aTargetObject,
   }
 
   // wrap the target object...
-  JSContext *cx = (JSContext *)scriptContext->GetNativeContext();
-  JSObject *scriptObject = nsnull;
-
-  nsCOMPtr<nsIXPConnectJSObjectHolder> holder;
-  nsContentUtils::XPConnect()->WrapNative(cx, sgo->GetGlobalJSObject(),
-                                          aTargetObject,
-                                          NS_GET_IID(nsISupports),
-                                          getter_AddRefs(holder));
-  if (holder) {
-    holder->GetJSObject(&scriptObject);
-  }
-
-  // Fail if wrapping the native object failed...
-  if (!scriptObject) {
-    return NS_ERROR_FAILURE;
-  }
-
+  nsCOMPtr<nsIScriptBinding> scriptBinding;
+  void *scope = sgo->GetLanguageGlobal(scriptContext->GetLanguage());
+  rv = scriptContext->GetScriptBinding(aTargetObject, scope,
+                                       getter_AddRefs(scriptBinding));
+  NS_ENSURE_SUCCESS(rv, rv);
   // Build up the array of argument names...
   //
   // Since this array is temporary (and const) the 'argument name' strings
@@ -277,7 +265,7 @@ nsHTMLScriptEventHandler::Invoke(nsISupports *aTargetObject,
   void* funcObject = nsnull;
   NS_NAMED_LITERAL_CSTRING(funcName, "anonymous");
 
-  rv = scriptContext->CompileFunction(scriptObject,
+  rv = scriptContext->CompileFunction(scriptBinding,
                                       funcName,   // method name
                                       argc,       // no of arguments
                                       args,       // argument names
@@ -297,9 +285,13 @@ nsHTMLScriptEventHandler::Invoke(nsISupports *aTargetObject,
   }
 
   // Invoke the event handler script...
-  jsval dummy;
-  return scriptContext->CallEventHandler(scriptObject, (JSObject *)funcObject,
-                                         aArgCount, (jsval *)aArgs, &dummy);
+  // eeek - jsval <-> nsISupports???
+  nsIArray *arg = nsnull;
+  nsISupports *ret = nsnull;
+  
+  
+  return scriptContext->CallEventHandler(scriptBinding, funcObject,
+                                         arg, &ret);
 }
 
 
diff --git a/mozilla/content/xbl/src/nsXBLDocumentInfo.cpp b/mozilla/content/xbl/src/nsXBLDocumentInfo.cpp
index c9ac8d15c3c..fc30ca99e7f 100644
--- a/mozilla/content/xbl/src/nsXBLDocumentInfo.cpp
+++ b/mozilla/content/xbl/src/nsXBLDocumentInfo.cpp
@@ -42,6 +42,7 @@
 #include "nsIScriptObjectPrincipal.h"
 #include "nsIScriptGlobalObject.h"
 #include "nsIScriptContext.h"
+#include "nsILanguageRuntime.h"
 #include "nsIDOMScriptObjectFactory.h"
 #include "jsapi.h"
 #include "nsIURI.h"
@@ -50,6 +51,10 @@
 #include "nsIChromeRegistry.h"
 #include "nsIPrincipal.h"
 
+#include "nsDOMJSUtils.h" // for GetScriptContextFromJSContext
+
+class nsIArray;
+
 static NS_DEFINE_CID(kDOMScriptObjectFactoryCID, NS_DOM_SCRIPT_OBJECT_FACTORY_CID);
 
 // An XBLDocumentInfo object has a special context associated with it which we can use to pre-compile 
@@ -65,6 +70,12 @@ public:
   
   // nsIScriptGlobalObject methods
   virtual void SetContext(nsIScriptContext *aContext);
+  virtual nsresult SetLanguageContext(PRUint32 lang_id, nsIScriptContext *aContext) {
+    NS_ASSERTION(lang_id == nsIProgrammingLanguage::JAVASCRIPT, "Only JS allowed!");
+    SetContext(aContext);
+    return NS_OK;
+  }
+
   virtual nsIScriptContext *GetContext();
   virtual nsresult SetNewDocument(nsIDOMDocument *aDocument,
                                   nsISupports *aState,
@@ -81,9 +92,20 @@ public:
                                   PRUint32 aFlags,
                                   nsEventStatus* aEventStatus);
   virtual JSObject *GetGlobalJSObject();
-  virtual void OnFinalize(JSObject *aObject);
+  virtual void OnFinalize();
   virtual void SetScriptsEnabled(PRBool aEnabled, PRBool aFireTimeouts);
-  virtual nsresult SetNewArguments(JSObject *aArguments);
+  virtual nsresult SetNewArguments(nsIArray *aArguments);
+
+  virtual nsIScriptContext *GetLanguageContext(PRUint32 language) {
+            // This impl still assumes JS
+            NS_ENSURE_TRUE(language==nsIProgrammingLanguage::JAVASCRIPT, nsnull);
+            return GetContext();
+  }
+  virtual void *GetLanguageGlobal(PRUint32 language) {
+            // This impl still assumes JS
+            NS_ENSURE_TRUE(language==nsIProgrammingLanguage::JAVASCRIPT, nsnull);
+            return GetGlobalJSObject();
+  }
 
   // nsIScriptObjectPrincipal methods
   virtual nsIPrincipal* GetPrincipal();
@@ -104,8 +126,12 @@ void PR_CALLBACK nsXBLDocGlobalObject_finalize(JSContext *cx, JSObject *obj)
 
   nsCOMPtr<nsIScriptGlobalObject> sgo(do_QueryInterface(nativeThis));
 
-  if (sgo)
-      sgo->OnFinalize(obj);
+  if (sgo) {
+    // We previously passed 'obj' to OnFinalize which did this check...
+    NS_ASSERTION(obj == sgo->GetLanguageGlobal(nsIProgrammingLanguage::JAVASCRIPT),
+                 "Finalizing global that doesn't have our global obj");
+    sgo->OnFinalize();
+  }
 
   // The addref was part of JSObject construction
   NS_RELEASE(nativeThis);
@@ -180,28 +206,52 @@ void
 nsXBLDocGlobalObject::SetContext(nsIScriptContext *aContext)
 {
   mScriptContext = aContext;
-  if (mScriptContext) {
-    JSContext* cx = (JSContext *)mScriptContext->GetNativeContext();
-    JS_SetErrorReporter(cx, XBL_ProtoErrorReporter);
-  }
 }
 
-
 nsIScriptContext *
 nsXBLDocGlobalObject::GetContext()
 {
   // This whole fragile mess is predicated on the fact that
-  // GetContext() will be called before GetScriptObject() is.
+  // GetContext() will be called before GetScriptObject()/SetLanguageContext() is.
   if (! mScriptContext) {
     nsCOMPtr<nsIDOMScriptObjectFactory> factory = do_GetService(kDOMScriptObjectFactoryCID);
     NS_ENSURE_TRUE(factory, nsnull);
 
-    nsresult rv =  factory->NewScriptContext(nsnull, getter_AddRefs(mScriptContext));
-    if (NS_FAILED(rv))
-        return nsnull;
+    // mScriptContext is actually set by PrepareScriptContext - so fetch our
+    // new context into a local
+    nsresult rv;
+    nsCOMPtr<nsILanguageRuntime> languageRuntime;
+    rv = factory->GetLanguageRuntimeByID(nsIProgrammingLanguage::JAVASCRIPT,
+                                         getter_AddRefs(languageRuntime));
+    NS_ENSURE_SUCCESS(rv, nsnull);
+    nsCOMPtr<nsIScriptContext> newCtx;
+    rv = languageRuntime->CreateContext(getter_AddRefs(newCtx));
+    NS_ENSURE_SUCCESS(rv, nsnull);
+    // For some reason, this new context is setup for *no* global object.
+    // This means we can't call our standard PrepareScriptEnvironment, as that
+    // associates the new context with ourself as the global.
+    // XXX - this also exists in nsXULPrototypeDocument
+
+    // This is similar to nsXULPrototypeDocument::SetLanguageContext, but
+    // we don't yet support multiple languages.
+    newCtx->WillInitializeContext();
+
+    // Bind the script context and the global object
+    rv = newCtx->InitContext(nsnull); // <- null here is different
+    NS_ENSURE_SUCCESS(rv, nsnull);
+  
+    newCtx->DidInitializeContext();
+    // bogus!  Maybe SetContext can die.
+    SetContext(newCtx);
+    // end of clone.
+    //rv = PrepareScriptEnvironment(nsIProgrammingLanguage::JAVASCRIPT, newCtx);
+    //NS_ENSURE_SUCCESS(rv, nsnull);
 
     JSContext *cx = (JSContext *)mScriptContext->GetNativeContext();
 
+    // nsJSEnvironment set the error reporter to NS_ScriptErrorReporter
+    // 
+    // I guess we need to reset it.
     JS_SetErrorReporter(cx, XBL_ProtoErrorReporter);
     mJSObject = ::JS_NewObject(cx, &gSharedGlobalClass, nsnull, nsnull);
     if (!mJSObject)
@@ -295,10 +345,12 @@ nsXBLDocGlobalObject::GetGlobalJSObject()
 }
 
 void
-nsXBLDocGlobalObject::OnFinalize(JSObject *aObject)
+nsXBLDocGlobalObject::OnFinalize()
 {
-  NS_ASSERTION(aObject == mJSObject, "Wrong object finalized!");
-
+  if (mScriptContext) {
+    mScriptContext->FinalizeClasses(mJSObject);
+    mScriptContext = nsnull;
+  }
   mJSObject = nsnull;
 }
 
@@ -309,7 +361,7 @@ nsXBLDocGlobalObject::SetScriptsEnabled(PRBool aEnabled, PRBool aFireTimeouts)
 }
 
 nsresult
-nsXBLDocGlobalObject::SetNewArguments(JSObject *aArguments)
+nsXBLDocGlobalObject::SetNewArguments(nsIArray *aArguments)
 {
   NS_NOTREACHED("waaah!");
   return NS_ERROR_UNEXPECTED;
@@ -372,7 +424,7 @@ nsXBLDocumentInfo::~nsXBLDocumentInfo()
 {
   /* destructor code */
   if (mGlobalObject) {
-    mGlobalObject->SetContext(nsnull); // remove circular reference
+    mGlobalObject->OnFinalize();
     mGlobalObject->SetGlobalObjectOwner(nsnull); // just in case
   }
   delete mBindingTable;
diff --git a/mozilla/content/xbl/src/nsXBLProtoImplField.cpp b/mozilla/content/xbl/src/nsXBLProtoImplField.cpp
index 5033f2a3350..066d3202cde 100644
--- a/mozilla/content/xbl/src/nsXBLProtoImplField.cpp
+++ b/mozilla/content/xbl/src/nsXBLProtoImplField.cpp
@@ -103,9 +103,8 @@ nsXBLProtoImplField::InstallMember(nsIScriptContext* aContext,
     return NS_OK; // nothing to do.
 
   JSContext* cx = (JSContext*) aContext->GetNativeContext();
-  JSObject * scriptObject = (JSObject *) aScriptObject;
-  NS_ASSERTION(scriptObject, "uh-oh, script Object should NOT be null or bad things will happen");
-  if (!scriptObject)
+  NS_ASSERTION(aScriptObject, "uh-oh, script Object should NOT be null or bad things will happen");
+  if (!aScriptObject)
     return NS_ERROR_FAILURE;
 
   nsCAutoString bindingURI(aClassStr);
@@ -120,7 +119,7 @@ nsXBLProtoImplField::InstallMember(nsIScriptContext* aContext,
   nsCOMPtr<nsIScriptContext> context = aContext;
   nsresult rv = context->EvaluateStringWithValue(nsDependentString(mFieldText,
                                                                    mFieldTextLength), 
-                                                 scriptObject,
+                                                 aScriptObject,
                                                  nsnull, bindingURI.get(),
                                                  mLineNumber, nsnull,
                                                  (void*) &result, &undefined);
@@ -130,7 +129,8 @@ nsXBLProtoImplField::InstallMember(nsIScriptContext* aContext,
   if (!undefined) {
     // Define the evaluated result as a JS property
     nsDependentString name(mName);
-    if (!::JS_DefineUCProperty(cx, scriptObject, NS_REINTERPRET_CAST(const jschar*, mName), 
+    if (!::JS_DefineUCProperty(cx, NS_REINTERPRET_CAST(JSObject *, aScriptObject),
+                               NS_REINTERPRET_CAST(const jschar*, mName), 
                                name.Length(), result, nsnull, nsnull, mJSAttributes))
       return NS_ERROR_OUT_OF_MEMORY;
   }
diff --git a/mozilla/content/xbl/src/nsXBLPrototypeHandler.cpp b/mozilla/content/xbl/src/nsXBLPrototypeHandler.cpp
index 12515d404df..5217592d859 100644
--- a/mozilla/content/xbl/src/nsXBLPrototypeHandler.cpp
+++ b/mozilla/content/xbl/src/nsXBLPrototypeHandler.cpp
@@ -441,34 +441,28 @@ nsXBLPrototypeHandler::ExecuteHandler(nsIDOMEventReceiver* aReceiver,
   nsIScriptContext *boundContext = boundGlobal->GetContext();
   if (!boundContext) return NS_OK;
 
-  JSObject* scriptObject = nsnull;
-
-  // strong ref to a GC root we'll need to protect scriptObject in the case
-  // where it is not the global object (!winRoot).
-  nsCOMPtr<nsIXPConnectJSObjectHolder> wrapper;
+  nsCOMPtr<nsIScriptBinding> scriptBinding;
+  void *scope = boundGlobal->GetLanguageGlobal(boundContext->GetLanguage());
 
+  // ack - this is wrong.  Old code always used aReceiver as the target, but
+  // here the global object itself suddenly is.
   if (winRoot) {
-    scriptObject = boundGlobal->GetGlobalJSObject();
+    // create a binding to the root.
+    NS_WARNING("EEEEK - I'm a but sus on this!?");
+    rv = boundContext->GetScriptBinding(boundGlobal, scope,
+                                        getter_AddRefs(scriptBinding));
   } else {
-    JSObject *global = boundGlobal->GetGlobalJSObject();
-    JSContext *cx = (JSContext *)boundContext->GetNativeContext();
-
-    // XXX: Don't use the global object!
-    rv = nsContentUtils::XPConnect()->WrapNative(cx, global, aReceiver,
-                                                 NS_GET_IID(nsISupports),
-                                                 getter_AddRefs(wrapper));
-    NS_ENSURE_SUCCESS(rv, rv);
-
-    rv = wrapper->GetJSObject(&scriptObject);
-    NS_ENSURE_SUCCESS(rv, rv);
+    rv = boundContext->GetScriptBinding(aReceiver, scope,
+                                        getter_AddRefs(scriptBinding));
   }
+  if (NS_FAILED(rv)) return rv;
 
   const char *eventName = nsContentUtils::GetEventArgName(kNameSpaceID_XBL);
 
   if (isXULKey) {
     nsCAutoString documentURI;
     keyCommandContent->GetOwnerDoc()->GetDocumentURI()->GetSpec(documentURI);
-    rv = boundContext->CompileEventHandler(scriptObject, onEventAtom, eventName,
+    rv = boundContext->CompileEventHandler(scriptBinding, onEventAtom, eventName,
                                            xulText, documentURI.get(), 0, 
                                            PR_TRUE, &handler);
   }
@@ -480,19 +474,19 @@ nsXBLPrototypeHandler::ExecuteHandler(nsIDOMEventReceiver* aReceiver,
     nsCAutoString bindingURI;
     mPrototypeBinding->DocURI()->GetSpec(bindingURI);
     
-    rv = boundContext->CompileEventHandler(scriptObject, onEventAtom, eventName,
+    rv = boundContext->CompileEventHandler(scriptBinding, onEventAtom, eventName,
                                            handlerText, bindingURI.get(),
                                            mLineNumber, PR_TRUE, &handler);
   }
   NS_ENSURE_SUCCESS(rv, rv);
 
   // Temporarily bind it to the bound element
-  boundContext->BindCompiledEventHandler(scriptObject, onEventAtom, handler);
+  boundContext->BindCompiledEventHandler(scriptBinding, onEventAtom, handler);
 
   // Execute it.
   nsCOMPtr<nsIDOMEventListener> eventListener;
-  NS_NewJSEventListener(boundContext, boundGlobal->GetGlobalJSObject(),
-                        aReceiver, getter_AddRefs(eventListener));
+  NS_NewJSEventListener(boundContext, boundGlobal,
+                        scriptBinding, getter_AddRefs(eventListener));
 
   nsCOMPtr<nsIJSEventListener> jsListener(do_QueryInterface(eventListener));
   jsListener->SetEventName(onEventAtom);
diff --git a/mozilla/content/xul/content/src/nsXULAtomList.h b/mozilla/content/xul/content/src/nsXULAtomList.h
index 29700fbeecf..e50db75b99d 100644
--- a/mozilla/content/xul/content/src/nsXULAtomList.h
+++ b/mozilla/content/xul/content/src/nsXULAtomList.h
@@ -316,3 +316,4 @@ XUL_ATOM(flexgroup, "flexgroup")
 XUL_ATOM(hidden, "hidden")
 XUL_ATOM(statustext, "statustext")
 XUL_ATOM(disabled, "disabled")
+XUL_ATOM(scriptLanguage, "scriptLanguage")
diff --git a/mozilla/content/xul/content/src/nsXULElement.cpp b/mozilla/content/xul/content/src/nsXULElement.cpp
index 0597945eea7..456a40d295e 100644
--- a/mozilla/content/xul/content/src/nsXULElement.cpp
+++ b/mozilla/content/xul/content/src/nsXULElement.cpp
@@ -190,6 +190,7 @@ nsICSSOMFactory* nsXULElement::gCSSOMFactory = nsnull;
 
 static NS_DEFINE_CID(kXULPopupListenerCID,        NS_XULPOPUPLISTENER_CID);
 static NS_DEFINE_CID(kCSSOMFactoryCID,            NS_CSSOMFACTORY_CID);
+static NS_DEFINE_CID(kDOMScriptObjectFactoryCID, NS_DOM_SCRIPT_OBJECT_FACTORY_CID);
 
 //----------------------------------------------------------------------
 
@@ -207,57 +208,6 @@ static struct {
 } gFaults;
 #endif
 
-#include "nsIJSRuntimeService.h"
-static nsIJSRuntimeService* gJSRuntimeService = nsnull;
-static JSRuntime* gScriptRuntime = nsnull;
-static PRInt32 gScriptRuntimeRefcnt = 0;
-
-static nsresult
-AddJSGCRoot(void* aScriptObjectRef, const char* aName)
-{
-    if (++gScriptRuntimeRefcnt == 1 || !gScriptRuntime) {
-        CallGetService("@mozilla.org/js/xpc/RuntimeService;1",
-                       &gJSRuntimeService);
-        if (! gJSRuntimeService) {
-            NS_NOTREACHED("couldn't add GC root");
-            return NS_ERROR_FAILURE;
-        }
-
-        gJSRuntimeService->GetRuntime(&gScriptRuntime);
-        if (! gScriptRuntime) {
-            NS_NOTREACHED("couldn't add GC root");
-            return NS_ERROR_FAILURE;
-        }
-    }
-
-    PRBool ok;
-    ok = ::JS_AddNamedRootRT(gScriptRuntime, aScriptObjectRef, aName);
-    if (! ok) {
-        NS_NOTREACHED("couldn't add GC root");
-        return NS_ERROR_OUT_OF_MEMORY;
-    }
-
-    return NS_OK;
-}
-
-static nsresult
-RemoveJSGCRoot(void* aScriptObjectRef)
-{
-    if (! gScriptRuntime) {
-        NS_NOTREACHED("couldn't remove GC root");
-        return NS_ERROR_FAILURE;
-    }
-
-    ::JS_RemoveRootRT(gScriptRuntime, aScriptObjectRef);
-
-    if (--gScriptRuntimeRefcnt == 0) {
-        NS_RELEASE(gJSRuntimeService);
-        gScriptRuntime = nsnull;
-    }
-
-    return NS_OK;
-}
-
 //----------------------------------------------------------------------
 
 
@@ -409,11 +359,27 @@ nsXULElement::Create(nsXULPrototypeElement* aPrototype,
     aPrototype->AddRef();
 
     if (aIsScriptable) {
+        // If this element defines a "scriptLanguage" element locate the ID
+        PRUint32 lang_id = nsIProgrammingLanguage::JAVASCRIPT;
+        nsAutoString languageAttr;
+        element->GetAttr(kNameSpaceID_None, nsXULAtoms::scriptLanguage,
+                         languageAttr);
+        if (!languageAttr.IsEmpty()) {
+            // convert name to language ID
+            nsCOMPtr<nsIDOMScriptObjectFactory> factory = \
+                    do_GetService(kDOMScriptObjectFactoryCID);
+            NS_ENSURE_TRUE(factory, NS_ERROR_FAILURE);
+            rv = factory->GetIDForLanguage(languageAttr, &lang_id);
+            NS_ASSERTION(NS_SUCCEEDED(rv),
+                         "Failed to locate script language - assuming js");
+        }
+
         // Check each attribute on the prototype to see if we need to do
         // any additional processing and hookup that would otherwise be
         // done 'automagically' by SetAttr().
         for (PRUint32 i = 0; i < aPrototype->mNumAttributes; ++i)
-            element->AddListenerFor(aPrototype->mAttributes[i].mName, PR_TRUE);
+            element->AddListenerFor(aPrototype->mAttributes[i].mName, lang_id,
+                                    PR_TRUE);
     }
 
     NS_ADDREF(*aResult = element.get());
@@ -626,7 +592,8 @@ nsXULElement::MaybeTriggerAutoLink(nsIDocShell *aShell)
 }
 
 nsresult
-nsXULElement::AddScriptEventListener(nsIAtom* aName, const nsAString& aValue)
+nsXULElement::AddScriptEventListener(nsIAtom* aName, const nsAString& aValue,
+                                     PRUint32 aLanguage)
 {
     // XXX sXBL/XBL2 issue! Owner or current document?
     // Note that If it's current, then we need to hook up listeners on the root
@@ -662,8 +629,8 @@ nsXULElement::AddScriptEventListener(nsIAtom* aName, const nsAString& aValue)
 
     if (NS_FAILED(rv)) return rv;
 
-    return manager->AddScriptEventListener(target, aName, aValue, defer,
-                                           !nsContentUtils::IsChromeDoc(doc));
+    return manager->AddScriptEventListener(target, aName, aValue, aLanguage,
+                                           defer, !nsContentUtils::IsChromeDoc(doc));
 }
 
 nsresult
@@ -741,7 +708,7 @@ nsXULElement::GetCompiledEventHandler(nsIAtom *aName, void** aHandler)
 
 nsresult
 nsXULElement::CompileEventHandler(nsIScriptContext* aContext,
-                                  void* aTarget,
+                                  nsIScriptBinding* aTarget,
                                   nsIAtom *aName,
                                   const nsAString& aBody,
                                   const char* aURL,
@@ -749,16 +716,16 @@ nsXULElement::CompileEventHandler(nsIScriptContext* aContext,
                                   void** aHandler)
 {
     nsresult rv;
-    JSObject* scopeObject;
+    nsIScriptBinding *compileTarget;
 
     XUL_PROTOTYPE_ATTRIBUTE_METER(gNumCacheSets);
 
-    nsIScriptContext *context;
+    nsIScriptContext *compileContext;
     if (mPrototype) {
         // It'll be shared among the instances of the prototype.
         // Use null for the scope object when precompiling shared
         // prototype scripts.
-        scopeObject = nsnull;
+        compileTarget = nsnull;
 
         // Use the prototype document's special context.  Because
         // scopeObject is null, the JS engine has no other source of
@@ -781,27 +748,31 @@ nsXULElement::CompileEventHandler(nsIScriptContext* aContext,
         nsIScriptGlobalObject* global = globalOwner->GetScriptGlobalObject();
         NS_ENSURE_TRUE(global, NS_ERROR_UNEXPECTED);
 
-        context = global->GetContext();
+        compileContext = global->GetLanguageContext(aContext->GetLanguage());
+        // It could be possible the language has been setup on aContext but
+        // not on the global - we don't demand-create language contexts on the
+        // nsGlobalWindow
+        NS_ASSERTION(compileContext, "Failed to get a context of this language from the global!?");
     }
     else {
         // We don't have a prototype; do a one-off compile.
         NS_ASSERTION(aTarget != nsnull, "no prototype and no target?!");
-        scopeObject = NS_REINTERPRET_CAST(JSObject*, aTarget);
-        context = aContext;
+        compileTarget = aTarget;
+        compileContext = aContext;
     }
 
     // Compile the event handler
     const char *eventName = nsContentUtils::GetEventArgName(kNameSpaceID_XUL);
-    rv = context->CompileEventHandler(scopeObject, aName, eventName, aBody,
-                                      aURL, aLineNo, !scopeObject,
-                                      aHandler);
+    rv = compileContext->CompileEventHandler(compileTarget, aName, eventName,
+                                             aBody, aURL, aLineNo, !compileTarget,
+                                             aHandler);
     if (NS_FAILED(rv)) return rv;
 
-    if (! scopeObject) {
+    if (! compileTarget) {
         // If it's a shared handler, we need to bind the shared
         // function object to the real target.
 
-        // XXX: Shouldn't this use context and not aContext?
+        // XXX: Shouldn't this use compileContext and not aContext?
         rv = aContext->BindCompiledEventHandler(aTarget, aName, *aHandler);
         if (NS_FAILED(rv)) return rv;
     }
@@ -811,13 +782,10 @@ nsXULElement::CompileEventHandler(nsIScriptContext* aContext,
     if (attr) {
         XUL_PROTOTYPE_ATTRIBUTE_METER(gNumCacheFills);
         attr->mEventHandler = *aHandler;
+        attr->mEventContext = compileContext;
 
         if (attr->mEventHandler) {
-            JSContext *cx = (JSContext*) context->GetNativeContext();
-            if (!cx)
-                return NS_ERROR_UNEXPECTED;
-
-            rv = AddJSGCRoot(&attr->mEventHandler,
+            rv = compileContext->AddGCRoot(&attr->mEventHandler,
                              "nsXULPrototypeAttribute::mEventHandler");
             if (NS_FAILED(rv)) return rv;
         }
@@ -829,6 +797,7 @@ nsXULElement::CompileEventHandler(nsIScriptContext* aContext,
 
 void
 nsXULElement::AddListenerFor(const nsAttrName& aName,
+                             PRUint32 aLanguage,
                              PRBool aCompileEventHandlers)
 {
     // If appropriate, add a popup listener and/or compile the event
@@ -841,7 +810,7 @@ nsXULElement::AddListenerFor(const nsAttrName& aName,
         if (aCompileEventHandlers && IsEventHandler(attr)) {
             nsAutoString value;
             GetAttr(kNameSpaceID_None, attr, value);
-            AddScriptEventListener(attr, value);
+            AddScriptEventListener(attr, value, aLanguage);
         }
     }
 }
@@ -958,12 +927,27 @@ nsXULElement::BindToTree(nsIDocument* aDocument, nsIContent* aParent,
         // Shouldn't they depend on the owner document?  Or is this code just
         // misplaced, basically?
         
+        // If this element defines a "scriptLanguage" element locate the ID
+        PRUint32 lang_id = nsIProgrammingLanguage::JAVASCRIPT;
+        nsAutoString languageAttr;
+        GetAttr(kNameSpaceID_None, nsXULAtoms::scriptLanguage, languageAttr);
+        if (!languageAttr.IsEmpty()) {
+            // convert name to language ID
+            nsCOMPtr<nsIDOMScriptObjectFactory> factory = \
+                                do_GetService(kDOMScriptObjectFactoryCID);
+            NS_ENSURE_TRUE(factory, NS_ERROR_FAILURE);
+            nsresult rv;
+            rv = factory->GetIDForLanguage(languageAttr, &lang_id);
+            NS_ASSERTION(NS_SUCCEEDED(rv),
+                         "Failed to locate script language - assuming js");
+        }
+
         PRInt32 count = mAttrsAndChildren.AttrCount();
         PRBool haveLocalAttributes = (count > 0);
         PRInt32 i;
         for (i = 0; i < count; i++) {
             AddListenerFor(*mAttrsAndChildren.GetSafeAttrNameAt(i),
-                           aCompileEventHandlers);
+                           lang_id, aCompileEventHandlers);
         }
 
         if (mPrototype) {
@@ -979,7 +963,7 @@ nsXULElement::BindToTree(nsIDocument* aDocument, nsIContent* aParent,
                     continue;
                 }
 
-                AddListenerFor(protoattr->mName, aCompileEventHandlers);
+                AddListenerFor(protoattr->mName, lang_id, aCompileEventHandlers);
             }
         }
     }
@@ -1468,7 +1452,8 @@ nsXULElement::SetAttr(PRInt32 aNamespaceID, nsIAtom* aName, nsIAtom* aPrefix,
         // the attribute isn't set yet.
         MaybeAddPopupListener(aName);
         if (IsEventHandler(aName)) {
-            AddScriptEventListener(aName, aValue);
+            // XXX - script language for this stuff?
+            AddScriptEventListener(aName, aValue, nsIProgrammingLanguage::JAVASCRIPT);
         }
 
         // Hide chrome if needed
@@ -3016,7 +3001,10 @@ nsXULPrototypeAttribute::~nsXULPrototypeAttribute()
 {
     MOZ_COUNT_DTOR(nsXULPrototypeAttribute);
     if (mEventHandler)
-        RemoveJSGCRoot(&mEventHandler);
+        if (mEventContext)
+            mEventContext->RemoveGCRoot(&mEventHandler);
+        else
+            NS_ERROR("Handler without context - leaked GC root?");
 }
 
 
@@ -3027,7 +3015,7 @@ nsXULPrototypeAttribute::~nsXULPrototypeAttribute()
 
 nsresult
 nsXULPrototypeElement::Serialize(nsIObjectOutputStream* aStream,
-                                 nsIScriptContext* aContext,
+                                 nsIScriptGlobalObject* aGlobal,
                                  const nsCOMArray<nsINodeInfo> *aNodeInfos)
 {
     nsresult rv;
@@ -3072,27 +3060,34 @@ nsXULPrototypeElement::Serialize(nsIObjectOutputStream* aStream,
         switch (child->mType) {
         case eType_Element:
         case eType_Text:
-            rv |= child->Serialize(aStream, aContext, aNodeInfos);
+            rv |= child->Serialize(aStream, aGlobal, aNodeInfos);
             break;
         case eType_Script:
             rv |= aStream->Write32(child->mType);
             nsXULPrototypeScript* script = NS_STATIC_CAST(nsXULPrototypeScript*, child);
 
+            PRUint32 langID = script->mScriptContext->GetLanguage();
+            NS_ASSERTION(langID == nsIProgrammingLanguage::JAVASCRIPT,
+                         "Fix me for non JS languages");
+			if (langID != nsIProgrammingLanguage::JAVASCRIPT)
+				return NS_ERROR_UNEXPECTED;
+
             rv |= aStream->Write8(script->mOutOfLine);
             if (! script->mOutOfLine) {
-                rv |= script->Serialize(aStream, aContext, aNodeInfos);
+                rv |= script->Serialize(aStream, aGlobal, aNodeInfos);
             } else {
                 rv |= aStream->WriteCompoundObject(script->mSrcURI,
                                                    NS_GET_IID(nsIURI),
                                                    PR_TRUE);
 
-                if (script->mJSObject) {
+                if (script->mScriptObject && langID == nsIProgrammingLanguage::JAVASCRIPT) {
                     // This may return NS_OK without muxing script->mSrcURI's
                     // data into the FastLoad file, in the case where that
                     // muxed document is already there (written by a prior
                     // session, or by an earlier FastLoad episode during this
                     // session).
-                    rv |= script->SerializeOutOfLine(aStream, aContext);
+                    nsIScriptContext *context = aGlobal->GetLanguageContext(langID);
+                    rv |= script->SerializeOutOfLine(aStream, aGlobal);
                 }
             }
             break;
@@ -3104,7 +3099,7 @@ nsXULPrototypeElement::Serialize(nsIObjectOutputStream* aStream,
 
 nsresult
 nsXULPrototypeElement::Deserialize(nsIObjectInputStream* aStream,
-                                   nsIScriptContext* aContext,
+                                   nsIScriptGlobalObject* aGlobal,
                                    nsIURI* aDocumentURI,
                                    const nsCOMArray<nsINodeInfo> *aNodeInfos)
 {
@@ -3165,7 +3160,7 @@ nsXULPrototypeElement::Deserialize(nsIObjectInputStream* aStream,
                     return NS_ERROR_OUT_OF_MEMORY;
                 child->mType = childType;
 
-                rv |= child->Deserialize(aStream, aContext, aDocumentURI,
+                rv |= child->Deserialize(aStream, aGlobal, aDocumentURI,
                                          aNodeInfos);
                 break;
             case eType_Text:
@@ -3174,12 +3169,23 @@ nsXULPrototypeElement::Deserialize(nsIObjectInputStream* aStream,
                     return NS_ERROR_OUT_OF_MEMORY;
                 child->mType = childType;
 
-                rv |= child->Deserialize(aStream, aContext, aDocumentURI,
+                rv |= child->Deserialize(aStream, aGlobal, aDocumentURI,
                                          aNodeInfos);
                 break;
             case eType_Script: {
+                // Hmmm.  Theoretically we need to work out the script language,
+                // find a script context for that language, then delegate the serialize
+                // to that.
+                // But now we only know about JavaScript.
+                // We need to change the fast-load format.
+                nsIScriptContext *context = aGlobal->GetLanguageContext(nsIProgrammingLanguage::JAVASCRIPT);
+                if (!context) {
+                    // We must always be able to get JS
+                    NS_ERROR("Could not get JS language context???");
+                    return NS_ERROR_UNEXPECTED;
+                }
                 // language version/options obtained during deserialization.
-                nsXULPrototypeScript* script = new nsXULPrototypeScript(0, nsnull, PR_FALSE);
+                nsXULPrototypeScript* script = new nsXULPrototypeScript(context, 0, 0);
                 if (! script)
                     return NS_ERROR_OUT_OF_MEMORY;
                 child = script;
@@ -3187,12 +3193,12 @@ nsXULPrototypeElement::Deserialize(nsIObjectInputStream* aStream,
 
                 rv |= aStream->Read8(&script->mOutOfLine);
                 if (! script->mOutOfLine) {
-                    rv |= script->Deserialize(aStream, aContext, aDocumentURI,
+                    rv |= script->Deserialize(aStream, aGlobal, aDocumentURI,
                                               aNodeInfos);
                 } else {
                     rv |= aStream->ReadObject(PR_TRUE, getter_AddRefs(script->mSrcURI));
 
-                    rv |= script->DeserializeOutOfLine(aStream, aContext);
+                    rv |= script->DeserializeOutOfLine(aStream, aGlobal);
                 }
                 break;
             }
@@ -3274,32 +3280,42 @@ nsXULPrototypeElement::SetAttrAt(PRUint32 aPos, const nsAString& aValue,
 // nsXULPrototypeScript
 //
 
-nsXULPrototypeScript::nsXULPrototypeScript(PRUint32 aLineNo, const char *aVersion, PRBool aHasE4XOption)
+nsXULPrototypeScript::nsXULPrototypeScript(nsIScriptContext *aContext, PRUint32 aLineNo, PRUint32 aVersion)
     : nsXULPrototypeNode(eType_Script),
       mLineNo(aLineNo),
       mSrcLoading(PR_FALSE),
       mOutOfLine(PR_TRUE),
-      mHasE4XOption(aHasE4XOption),
       mSrcLoadWaiters(nsnull),
-      mJSObject(nsnull),
+      mScriptObject(nsnull),
+      mScriptContext(aContext),
       mLangVersion(aVersion)
 {
     NS_LOG_ADDREF(this, 1, ClassName(), ClassSize());
-    AddJSGCRoot(&mJSObject, "nsXULPrototypeScript::mJSObject");
+    aContext->AddGCRoot(&mScriptObject, "nsXULPrototypeScript::mScriptObject");
 }
 
 
 nsXULPrototypeScript::~nsXULPrototypeScript()
 {
-    RemoveJSGCRoot(&mJSObject);
+    if (mScriptContext)
+        mScriptContext->RemoveGCRoot(&mScriptObject);
+    else
+        NS_ERROR("nsXULPrototypeScript without context - leaked GC root?");
 }
 
 
 nsresult
 nsXULPrototypeScript::Serialize(nsIObjectOutputStream* aStream,
-                                nsIScriptContext* aContext,
+                                nsIScriptGlobalObject* aGlobal,
                                 const nsCOMArray<nsINodeInfo> *aNodeInfos)
 {
+    PRUint32 langID = mScriptContext->GetLanguage();
+    nsIScriptContext *context = aGlobal->GetLanguageContext(langID);
+    NS_ASSERTION(context == mScriptContext, "Contexts are confused?");
+    NS_ASSERTION(langID == nsIProgrammingLanguage::JAVASCRIPT, "Still only JS");
+    // todo - Write the language ID etc.
+    
+    JSObject *mJSObject = (JSObject *)mScriptObject; // eeek - this must be delegated??
     NS_ASSERTION(!mSrcLoading || mSrcLoadWaiters != nsnull || !mJSObject,
                  "script source still loading when serializing?!");
     if (!mJSObject)
@@ -3311,7 +3327,7 @@ nsXULPrototypeScript::Serialize(nsIObjectOutputStream* aStream,
     aStream->Write32(mLineNo);
 
     JSContext* cx = NS_REINTERPRET_CAST(JSContext*,
-                                        aContext->GetNativeContext());
+                                        context->GetNativeContext());
     JSXDRState *xdr = ::JS_XDRNewMem(cx, JSXDR_ENCODE);
     if (! xdr)
         return NS_ERROR_OUT_OF_MEMORY;
@@ -3349,10 +3365,7 @@ nsXULPrototypeScript::Serialize(nsIObjectOutputStream* aStream,
     ::JS_XDRDestroy(xdr);
     if (NS_FAILED(rv)) return rv;
 
-    PRUint32 version = PRUint32(mLangVersion
-                                ? ::JS_StringToVersion(mLangVersion)
-                                : JSVERSION_DEFAULT);
-    rv = aStream->Write32(version);
+    rv = aStream->Write32(mLangVersion);
     if (NS_FAILED(rv)) return rv;
 
     return NS_OK;
@@ -3360,8 +3373,13 @@ nsXULPrototypeScript::Serialize(nsIObjectOutputStream* aStream,
 
 nsresult
 nsXULPrototypeScript::SerializeOutOfLine(nsIObjectOutputStream* aStream,
-                                         nsIScriptContext* aContext)
+                                         nsIScriptGlobalObject* aGlobal)
 {
+    PRUint32 langID = mScriptContext->GetLanguage();
+    NS_ASSERTION(aGlobal->GetLanguageContext(langID) == mScriptContext,
+                 "Contexts are confused?");
+    NS_ASSERTION(langID == nsIProgrammingLanguage::JAVASCRIPT, "Still only JS");
+
     nsIXULPrototypeCache* cache = GetXULCache();
 #ifdef NS_DEBUG
     PRBool useXULCache = PR_TRUE;
@@ -3409,7 +3427,7 @@ nsXULPrototypeScript::SerializeOutOfLine(nsIObjectOutputStream* aStream,
 
     nsCOMPtr<nsIURI> oldURI;
     rv |= fastLoadService->SelectMuxedDocument(mSrcURI, getter_AddRefs(oldURI));
-    rv |= Serialize(objectOutput, aContext, nsnull);
+    rv |= Serialize(objectOutput, aGlobal, nsnull);
     rv |= fastLoadService->EndMuxedDocument(mSrcURI);
 
     if (oldURI) {
@@ -3426,13 +3444,19 @@ nsXULPrototypeScript::SerializeOutOfLine(nsIObjectOutputStream* aStream,
 
 nsresult
 nsXULPrototypeScript::Deserialize(nsIObjectInputStream* aStream,
-                                  nsIScriptContext* aContext,
+                                  nsIScriptGlobalObject* aGlobal,
                                   nsIURI* aDocumentURI,
                                   const nsCOMArray<nsINodeInfo> *aNodeInfos)
 {
+    PRUint32 langID = mScriptContext->GetLanguage();
+    NS_ASSERTION(aGlobal->GetLanguageContext(langID) == mScriptContext,
+                 "Contexts are confused?");
+    NS_ASSERTION(langID == nsIProgrammingLanguage::JAVASCRIPT, "Still only JS");
     NS_TIMELINE_MARK_FUNCTION("chrome js deserialize");
     nsresult rv;
 
+    JSObject *mJSObject = (JSObject *)mScriptObject; // eeek - this must be delegated??
+
     // Read basic prototype data
     aStream->Read32(&mLineNo);
 
@@ -3447,7 +3471,7 @@ nsXULPrototypeScript::Deserialize(nsIObjectInputStream* aStream,
     rv = aStream->ReadBytes(size, &data);
     if (NS_SUCCEEDED(rv)) {
         JSContext* cx = NS_REINTERPRET_CAST(JSContext*,
-                                            aContext->GetNativeContext());
+                                            aGlobal->GetContext()->GetNativeContext());
 
         JSXDRState *xdr = ::JS_XDRNewMem(cx, JSXDR_DECODE);
         if (! xdr) {
@@ -3501,22 +3525,26 @@ nsXULPrototypeScript::Deserialize(nsIObjectInputStream* aStream,
     }
     if (NS_FAILED(rv)) return rv;
 
-    PRUint32 version;
-    rv = aStream->Read32(&version);
+    rv = aStream->Read32(&mLangVersion);
     if (NS_FAILED(rv)) return rv;
 
-    mLangVersion = ::JS_VersionToString(JSVersion(version));
     return NS_OK;
 }
 
 
 nsresult
 nsXULPrototypeScript::DeserializeOutOfLine(nsIObjectInputStream* aInput,
-                                           nsIScriptContext* aContext)
+                                           nsIScriptGlobalObject* aGlobal)
 {
     // Keep track of FastLoad failure via rv, so we can
     // AbortFastLoads if things look bad.
     nsresult rv = NS_OK;
+    PRUint32 langID = mScriptContext->GetLanguage();
+    NS_ASSERTION(aGlobal->GetLanguageContext(langID) == mScriptContext,
+                 "Contexts are confused?");
+    NS_ASSERTION(langID == nsIProgrammingLanguage::JAVASCRIPT, "Still only JS");
+
+    JSObject *mJSObject = (JSObject *)mScriptObject; // eeek - this must be delegated??
 
     nsIXULPrototypeCache* cache = GetXULCache();
     nsCOMPtr<nsIFastLoadService> fastLoadService;
@@ -3577,7 +3605,7 @@ nsXULPrototypeScript::DeserializeOutOfLine(nsIObjectInputStream* aInput,
             // We're better off slow-loading than bailing out due to a
             // FastLoad error.
             if (NS_SUCCEEDED(rv))
-                rv = Deserialize(objectInput, aContext, nsnull, nsnull);
+                rv = Deserialize(objectInput, aGlobal, nsnull, nsnull);
 
             if (NS_SUCCEEDED(rv) && mSrcURI) {
                 rv = fastLoadService->EndMuxedDocument(mSrcURI);
@@ -3632,6 +3660,11 @@ nsXULPrototypeScript::Compile(const PRUnichar* aText,
     // and the first document would indirectly reference the prototype
     // document because it keeps the prototype cache alive. Circularity!
     nsresult rv;
+    // In a multi-language world, that means ignoring our mScriptContext
+    // other than to ask it for its language ID to get a matching context
+    // from the global.
+    PRUint32 lang_id = mScriptContext ? 
+                         mScriptContext->GetLanguage() : nsIProgrammingLanguage::JAVASCRIPT;
 
     // Use the prototype document's special context
     nsIScriptContext *context;
@@ -3644,8 +3677,7 @@ nsXULPrototypeScript::Compile(const PRUnichar* aText,
         if (! global)
             return NS_ERROR_UNEXPECTED;
 
-        context = global->GetContext();
-
+        context = global->GetLanguageContext(lang_id);
         NS_ASSERTION(context != nsnull, "no context for script global");
         if (! context)
             return NS_ERROR_UNEXPECTED;
@@ -3662,22 +3694,32 @@ nsXULPrototypeScript::Compile(const PRUnichar* aText,
 
     // Ok, compile it to create a prototype script object!
 
-    // XXXbe violate nsIScriptContext layering because its version parameter
-    // is mis-typed as const char * -- if it were uint32, we could more easily
-    // extend version to include compile-time option, as the JS engine does.
-    // It'd also be more efficient than converting to and from a C string.
+/** I think this is taken care of by nsIScriptContext->CompileScript - it
+ * saves and restores the version.
+ * 
+    // *sob* - what to do about these options?
+    NS_ENSURE_TRUE(cx, NS_ERROR_UNEXPECTED);
+    uint32 options = 0;
+    JSBool changed = PR_FALSE;
+    if (context->GetLanguage() == nsIProgrammingLanguage::JAVASCRIPT) {
 
-    JSContext* cx = NS_REINTERPRET_CAST(JSContext*,
-                                        context->GetNativeContext());
-    uint32 options = ::JS_GetOptions(cx);
-    JSBool changed = (mHasE4XOption ^ !!(options & JSOPTION_XML));
-    if (changed) {
-        ::JS_SetOptions(cx,
-                        mHasE4XOption
-                        ? options | JSOPTION_XML
-                        : options & ~JSOPTION_XML);
+        // XXXbe violate nsIScriptContext layering because its version parameter
+        // is mis-typed as const char * -- if it were uint32, we could more easily
+        // extend version to include compile-time option, as the JS engine does.
+        // It'd also be more efficient than converting to and from a C string.
+
+        JSContext* cx = NS_REINTERPRET_CAST(JSContext*,
+                                                                                context->GetNativeContext());
+        uint32 options = ::JS_GetOptions(cx);
+        JSBool changed = (mHasE4XOption ^ !!(options & JSOPTION_XML));
+        if (changed) {
+            ::JS_SetOptions(cx,
+                            mHasE4XOption
+                            ? options | JSOPTION_XML
+                            : options & ~JSOPTION_XML);
+        }
     }
-
+***/
     rv = context->CompileScript(aText,
                                 aTextLength,
                                 nsnull,
@@ -3685,11 +3727,16 @@ nsXULPrototypeScript::Compile(const PRUnichar* aText,
                                 urlspec.get(),
                                 aLineNo,
                                 mLangVersion,
-                                (void**)&mJSObject);
-
-    if (changed) {
-        ::JS_SetOptions(cx, options);
+                                (void**)&mScriptObject);
+/***
+    if (context->GetLanguage() == nsIProgrammingLanguage::JAVASCRIPT) {
+        if (changed) {
+            JSContext* cx = NS_REINTERPRET_CAST(JSContext*,
+                                                context->GetNativeContext());
+            ::JS_SetOptions(cx, options);
+        }
     }
+***/
     return rv;
 }
 
@@ -3700,7 +3747,7 @@ nsXULPrototypeScript::Compile(const PRUnichar* aText,
 
 nsresult
 nsXULPrototypeText::Serialize(nsIObjectOutputStream* aStream,
-                              nsIScriptContext* aContext,
+                              nsIScriptGlobalObject* aGlobal,
                               const nsCOMArray<nsINodeInfo> *aNodeInfos)
 {
     nsresult rv;
@@ -3715,7 +3762,7 @@ nsXULPrototypeText::Serialize(nsIObjectOutputStream* aStream,
 
 nsresult
 nsXULPrototypeText::Deserialize(nsIObjectInputStream* aStream,
-                                nsIScriptContext* aContext,
+                                nsIScriptGlobalObject* aGlobal,
                                 nsIURI* aDocumentURI,
                                 const nsCOMArray<nsINodeInfo> *aNodeInfos)
 {
diff --git a/mozilla/content/xul/content/src/nsXULElement.h b/mozilla/content/xul/content/src/nsXULElement.h
index 18abd7f6405..0a3646c55aa 100644
--- a/mozilla/content/xul/content/src/nsXULElement.h
+++ b/mozilla/content/xul/content/src/nsXULElement.h
@@ -118,6 +118,7 @@ class nsXULPrototypeAttribute
 public:
     nsXULPrototypeAttribute()
         : mName(nsXULAtoms::id),  // XXX this is a hack, but names have to have a value
+          mEventContext(nsnull),
           mEventHandler(nsnull)
     {
         XUL_PROTOTYPE_ATTRIBUTE_METER(gNumAttributes);
@@ -129,6 +130,7 @@ public:
     nsAttrName mName;
     nsAttrValue mValue;
     void* mEventHandler;
+    nsCOMPtr<nsIScriptContext> mEventContext; // used only so we can do context->RemoveGCRoot
 
 #ifdef XUL_PROTOTYPE_ATTRIBUTE_METERING
     /**
@@ -200,10 +202,10 @@ public:
 
     virtual ~nsXULPrototypeNode() {}
     virtual nsresult Serialize(nsIObjectOutputStream* aStream,
-                               nsIScriptContext* aContext,
+                               nsIScriptGlobalObject* aGlobal,
                                const nsCOMArray<nsINodeInfo> *aNodeInfos) = 0;
     virtual nsresult Deserialize(nsIObjectInputStream* aStream,
-                                 nsIScriptContext* aContext,
+                                 nsIScriptGlobalObject* aGlobal,
                                  nsIURI* aDocumentURI,
                                  const nsCOMArray<nsINodeInfo> *aNodeInfos) = 0;
 
@@ -268,10 +270,10 @@ public:
     }
 
     virtual nsresult Serialize(nsIObjectOutputStream* aStream,
-                               nsIScriptContext* aContext,
+                               nsIScriptGlobalObject* aGlobal,
                                const nsCOMArray<nsINodeInfo> *aNodeInfos);
     virtual nsresult Deserialize(nsIObjectInputStream* aStream,
-                                 nsIScriptContext* aContext,
+                                 nsIScriptGlobalObject* aGlobal,
                                  nsIURI* aDocumentURI,
                                  const nsCOMArray<nsINodeInfo> *aNodeInfos);
 
@@ -312,8 +314,7 @@ class nsXULDocument;
 class nsXULPrototypeScript : public nsXULPrototypeNode
 {
 public:
-    nsXULPrototypeScript(PRUint32 aLineNo, const char *aVersion,
-                         PRBool aHasE4XOption);
+    nsXULPrototypeScript(nsIScriptContext *aContext, PRUint32 aLineNo, PRUint32 version);
     virtual ~nsXULPrototypeScript();
 
 #ifdef NS_BUILD_REFCNT_LOGGING
@@ -322,16 +323,16 @@ public:
 #endif
 
     virtual nsresult Serialize(nsIObjectOutputStream* aStream,
-                               nsIScriptContext* aContext,
+                               nsIScriptGlobalObject* aGlobal,
                                const nsCOMArray<nsINodeInfo> *aNodeInfos);
     nsresult SerializeOutOfLine(nsIObjectOutputStream* aStream,
-                                nsIScriptContext* aContext);
+                                nsIScriptGlobalObject* aGlobal);
     virtual nsresult Deserialize(nsIObjectInputStream* aStream,
-                                 nsIScriptContext* aContext,
+                                 nsIScriptGlobalObject* aGlobal,
                                  nsIURI* aDocumentURI,
                                  const nsCOMArray<nsINodeInfo> *aNodeInfos);
     nsresult DeserializeOutOfLine(nsIObjectInputStream* aInput,
-                                  nsIScriptContext* aContext);
+                                  nsIScriptGlobalObject* aGlobal);
 
     nsresult Compile(const PRUnichar* aText, PRInt32 aTextLength,
                      nsIURI* aURI, PRUint32 aLineNo,
@@ -342,10 +343,10 @@ public:
     PRUint32                 mLineNo;
     PRPackedBool             mSrcLoading;
     PRPackedBool             mOutOfLine;
-    PRPackedBool             mHasE4XOption;
     nsXULDocument*           mSrcLoadWaiters;   // [OWNER] but not COMPtr
-    JSObject*                mJSObject;
-    const char*              mLangVersion;
+    nsCOMPtr<nsIScriptContext> mScriptContext;
+    void *                   mScriptObject;
+    PRUint32                 mLangVersion;
 
     static void ReleaseGlobals()
     {
@@ -382,10 +383,10 @@ public:
 #endif
 
     virtual nsresult Serialize(nsIObjectOutputStream* aStream,
-                               nsIScriptContext* aContext,
+                               nsIScriptGlobalObject* aGlobal,
                                const nsCOMArray<nsINodeInfo> *aNodeInfos);
     virtual nsresult Deserialize(nsIObjectInputStream* aStream,
-                                 nsIScriptContext* aContext,
+                                 nsIScriptGlobalObject* aGlobal,
                                  nsIURI* aDocumentURI,
                                  const nsCOMArray<nsINodeInfo> *aNodeInfos);
 
@@ -544,7 +545,8 @@ public:
     PRBool GetLazyState(LazyState aFlag)
     { return GetFlags() & (aFlag << XUL_ELEMENT_LAZY_STATE_OFFSET); }
     NS_HIDDEN_(nsresult) AddScriptEventListener(nsIAtom* aName,
-                                                const nsAString& aValue);
+                                                const nsAString& aValue,
+                                                PRUint32 aLanguage);
 
     // nsIDOMNode
     NS_FORWARD_NSIDOMNODE_NO_CLONENODE(nsGenericElement::)
@@ -557,7 +559,7 @@ public:
 
     // nsIScriptEventHandlerOwner
     nsresult CompileEventHandler(nsIScriptContext* aContext,
-                                 void* aTarget,
+                                 nsIScriptBinding* aTarget,
                                  nsIAtom *aName,
                                  const nsAString& aBody,
                                  const char* aURL,
@@ -614,6 +616,7 @@ protected:
      * Add a listener for the specified attribute, if appropriate.
      */
     void AddListenerFor(const nsAttrName& aName,
+                        PRUint32 aScriptLanguage,
                         PRBool aCompileEventHandlers);
     void MaybeAddPopupListener(nsIAtom* aLocalName);
 
diff --git a/mozilla/content/xul/document/src/nsXULContentSink.cpp b/mozilla/content/xul/document/src/nsXULContentSink.cpp
index 47a3ec0836b..e02d732f5ef 100644
--- a/mozilla/content/xul/document/src/nsXULContentSink.cpp
+++ b/mozilla/content/xul/document/src/nsXULContentSink.cpp
@@ -69,6 +69,7 @@
 #include "nsIParser.h"
 #include "nsIPresShell.h"
 #include "nsIScriptContext.h"
+#include "nsILanguageRuntime.h"
 #include "nsIScriptGlobalObject.h"
 #include "nsIServiceManager.h"
 #include "nsITextContent.h"
@@ -113,6 +114,7 @@ static PRLogModuleInfo* gLog;
 #endif
 
 static NS_DEFINE_CID(kXULPrototypeCacheCID,      NS_XULPROTOTYPECACHE_CID);
+static NS_DEFINE_CID(kDOMScriptObjectFactoryCID, NS_DOM_SCRIPT_OBJECT_FACTORY_CID);
 
 //----------------------------------------------------------------------
 
@@ -821,7 +823,7 @@ XULContentSinkImpl::HandleEndElement(const PRUnichar *aName)
             NS_STATIC_CAST(nsXULPrototypeScript*, node);
 
         // If given a src= attribute, we must ignore script tag content.
-        if (! script->mSrcURI && ! script->mJSObject) {
+        if (! script->mSrcURI && ! script->mScriptObject) {
             nsCOMPtr<nsIDocument> doc = do_QueryReferent(mDocument);
 
             script->mOutOfLine = PR_FALSE;
@@ -1177,9 +1179,13 @@ XULContentSinkImpl::OpenScript(const PRUnichar** aAttributes,
                                const PRUint32 aLineNumber)
 {
   nsresult rv = NS_OK;
-  PRBool isJavaScript = PR_TRUE;
-  PRBool hasE4XOption = PR_TRUE;
-  const char* jsVersionString = nsnull;
+
+  nsCOMPtr<nsIDOMScriptObjectFactory> factory = do_GetService(kDOMScriptObjectFactoryCID);
+  NS_ENSURE_TRUE(factory, nsnull);
+  
+  nsCOMPtr<nsILanguageRuntime> languageRuntime;
+  PRUint32 version = 0;
+  PRBool seenLanguage = PR_FALSE ; // have we seen a language specified?
 
   // Look for SRC attribute and look for a LANGUAGE attribute
   nsAutoString src;
@@ -1189,6 +1195,7 @@ XULContentSinkImpl::OpenScript(const PRUnichar** aAttributes,
           src.Assign(aAttributes[1]);
       }
       else if (key.EqualsLiteral("type")) {
+          seenLanguage = PR_TRUE;
           nsCOMPtr<nsIMIMEHeaderParam> mimeHdrParser =
               do_GetService("@mozilla.org/network/mime-hdrparam;1");
           NS_ENSURE_TRUE(mimeHdrParser, NS_ERROR_FAILURE);
@@ -1201,6 +1208,7 @@ XULContentSinkImpl::OpenScript(const PRUnichar** aAttributes,
                                            mimeType);
           NS_ENSURE_SUCCESS(rv, rv);
 
+          // Javascript keeps the fast path, optimized for most-likely type
           // Table ordered from most to least likely JS MIME types. For .xul
           // files that we host, the likeliest type is application/x-javascript.
           // See bug 62485, feel free to add <script type="..."> survey data to it,
@@ -1213,63 +1221,107 @@ XULContentSinkImpl::OpenScript(const PRUnichar** aAttributes,
               "application/ecmascript",
               nsnull
           };
-
-          isJavaScript = PR_FALSE;
+  
+          PRBool isJavaScript = PR_FALSE;
           for (PRInt32 i = 0; jsTypes[i]; i++) {
               if (mimeType.LowerCaseEqualsASCII(jsTypes[i])) {
                   isJavaScript = PR_TRUE;
                   break;
               }
           }
-
-          if (isJavaScript) {
-              JSVersion jsVersion = JSVERSION_DEFAULT;
-              nsAutoString value;
-              rv = mimeHdrParser->GetParameter(typeAndParams, "version",
-                                               EmptyCString(), PR_FALSE, nsnull,
-                                               value);
-              if (NS_FAILED(rv)) {
-                  if (rv != NS_ERROR_INVALID_ARG)
-                      return rv;
-              } else {
-                  if (value.Length() != 3 || value[0] != '1' || value[1] != '.')
-                      jsVersion = JSVERSION_UNKNOWN;
-                  else switch (value[2]) {
-                      case '0': jsVersion = JSVERSION_1_0; break;
-                      case '1': jsVersion = JSVERSION_1_1; break;
-                      case '2': jsVersion = JSVERSION_1_2; break;
-                      case '3': jsVersion = JSVERSION_1_3; break;
-                      case '4': jsVersion = JSVERSION_1_4; break;
-                      case '5': jsVersion = JSVERSION_1_5; break;
-                      default:  jsVersion = JSVERSION_UNKNOWN;
-                  }
-              }
-              jsVersionString = ::JS_VersionToString(jsVersion);
-
-              rv = mimeHdrParser->GetParameter(typeAndParams, "e4x",
-                                               EmptyCString(), PR_FALSE, nsnull,
-                                               value);
-              if (NS_FAILED(rv)) {
-                  if (rv != NS_ERROR_INVALID_ARG)
-                      return rv;
-              } else {
-                  if (value.Length() == 1 && value[0] == '0')
-                      hasE4XOption = PR_FALSE;
-              }
+          if (isJavaScript)
+            rv = factory->GetLanguageRuntimeByID(nsIProgrammingLanguage::JAVASCRIPT,
+                                                getter_AddRefs(languageRuntime));
+          else
+            // Use the script object factory to locate a matching language.
+            rv = factory->GetLanguageRuntime(mimeType, getter_AddRefs(languageRuntime));
+          if (NS_FAILED(rv) || languageRuntime == nsnull) {
+            NS_WARNING("Failed to find a scripting language");
+            return NS_FAILED(rv) ? rv : NS_ERROR_UNEXPECTED;
+          }
+          // Get the version string, and ensure the language supports it.
+          nsAutoString versionName;
+          rv = mimeHdrParser->GetParameter(typeAndParams, "version",
+                                           EmptyCString(), PR_FALSE, nsnull,
+                                           versionName);
+          if (NS_FAILED(rv)) {
+            // no language specified - verion remains 0.
+            if (rv != NS_ERROR_INVALID_ARG)
+              return rv;
+          } else {
+            rv = languageRuntime->ParseVersion(versionName, &version);
+            if (NS_FAILED(rv)) {
+              NS_WARNING("This script language version is not supported - ignored");
+              return rv;
+            }
+          }
+          // Some js specifics yet to be abstracted.
+          if (languageRuntime->GetLanguage() == nsIProgrammingLanguage::JAVASCRIPT) {
+            nsAutoString value;
+            rv = mimeHdrParser->GetParameter(typeAndParams, "e4x",
+                                             EmptyCString(), PR_FALSE, nsnull,
+                                             value);
+            if (NS_FAILED(rv)) {
+                if (rv != NS_ERROR_INVALID_ARG)
+                    return rv;
+            } else {
+                if (value.Length() == 1 && value[0] == '0')
+                    version |= JSOPTION_XML;
+            }
           }
       }
       else if (key.EqualsLiteral("language")) {
+        // Language is deprecated, and the impl in nsScriptLoader ignores the
+        // various version strings anyway.  So we make no attempt to support
+        // languages other than JS for language=
           nsAutoString lang(aAttributes[1]);
-          isJavaScript =
-              nsParserUtils::IsJavaScriptLanguage(lang, &jsVersionString);
+          seenLanguage = PR_TRUE;
+          if (nsParserUtils::IsJavaScriptLanguage(lang, &version)) {
+            rv = factory->GetLanguageRuntimeByID(nsIProgrammingLanguage::JAVASCRIPT,
+                                                 getter_AddRefs(languageRuntime));
+            NS_ASSERTION(NS_SUCCEEDED(rv), "Failed to get javascript language");
+          }
       }
       aAttributes += 2;
   }
+  if (!seenLanguage) {
+    // no one tried to identify a language - JS is default.
+    // (If they did try to identify but it was unrecognized, we don't want to
+    // assume JS)
+    NS_ASSERTION(languageRuntime == nsnull, "eh?");
+    rv = factory->GetLanguageRuntimeByID(nsIProgrammingLanguage::JAVASCRIPT,
+                                         getter_AddRefs(languageRuntime));
+    NS_ASSERTION(!NS_FAILED(rv), "Failed to get default JavaScript language!");
+    // languageRuntime remains NULL - we will ignore it.
+  }
+  // Don't process scripts that aren't known
+  if (languageRuntime != nsnull) {
+      nsIScriptGlobalObject* globalObject = nsnull; // borrowed reference
+      nsIScriptContext* scriptContext = nsnull; // borrowed reference
+      nsCOMPtr<nsIDocument> doc(do_QueryReferent(mDocument));
+      if (doc)
+          globalObject = doc->GetScriptGlobalObject();
+      if (globalObject) {
+        scriptContext = globalObject->GetLanguageContext(languageRuntime->GetLanguage());
+        // hrm - I don't think this is the right place to do this, but here we go anyway...
+        if (scriptContext == nsnull) {
+          // first request for this programming language - set things up.
+          rv = languageRuntime->CreateContext(&scriptContext);
+          NS_ENSURE_SUCCESS(rv, nsnull);
+          rv = globalObject->SetLanguageContext(languageRuntime->GetLanguage(),
+                                                scriptContext);
+          NS_ENSURE_SUCCESS(rv, nsnull);
+          // globalObject now holds reference to context, but scriptContext
+          // has an extra one.
+          // NS_IF_RELEASE sets to NULL - not what we want.
+          scriptContext->Release();
+        }
+      }
+      NS_ASSERTION(scriptContext != nsnull, "no script context!");
+      NS_ENSURE_TRUE(scriptContext != nsnull, NS_ERROR_UNEXPECTED);
 
-  // Don't process scripts that aren't JavaScript
-  if (isJavaScript) {
       nsXULPrototypeScript* script =
-          new nsXULPrototypeScript(aLineNumber, jsVersionString, hasE4XOption);
+          new nsXULPrototypeScript(scriptContext, aLineNumber, version);
       if (! script)
           return NS_ERROR_OUT_OF_MEMORY;
 
@@ -1305,15 +1357,8 @@ XULContentSinkImpl::OpenScript(const PRUnichar** aAttributes,
           // file right away.  Otherwise we'll end up reloading the script and
           // corrupting the FastLoad file trying to serialize it, in the case
           // where it's already there.
-          nsCOMPtr<nsIDocument> doc(do_QueryReferent(mDocument));
-          if (doc) {
-              nsIScriptGlobalObject* globalObject = doc->GetScriptGlobalObject();
-              if (globalObject) {
-                  nsIScriptContext *scriptContext = globalObject->GetContext();
-                  if (scriptContext)
-                      script->DeserializeOutOfLine(nsnull, scriptContext);
-              }
-          }
+          if (globalObject)
+                script->DeserializeOutOfLine(nsnull, globalObject);
       }
 
       nsVoidArray* children;
diff --git a/mozilla/content/xul/document/src/nsXULDocument.cpp b/mozilla/content/xul/document/src/nsXULDocument.cpp
index 77bae7e8db9..c4be22f119e 100644
--- a/mozilla/content/xul/document/src/nsXULDocument.cpp
+++ b/mozilla/content/xul/document/src/nsXULDocument.cpp
@@ -2955,9 +2955,9 @@ nsXULDocument::ResumeWalk()
                     if (NS_SUCCEEDED(rv) && blocked)
                         return NS_OK;
                 }
-                else if (scriptproto->mJSObject) {
+                else if (scriptproto->mScriptObject) {
                     // An inline script
-                    rv = ExecuteScript(scriptproto->mJSObject);
+                    rv = ExecuteScript(scriptproto);
                     if (NS_FAILED(rv)) return rv;
                 }
             }
@@ -3268,8 +3268,8 @@ nsXULDocument::LoadScript(nsXULPrototypeScript* aScriptProto, PRBool* aBlock)
     // Load a transcluded script
     nsresult rv;
 
-    if (aScriptProto->mJSObject) {
-        rv = ExecuteScript(aScriptProto->mJSObject);
+    if (aScriptProto->mScriptObject) {
+        rv = ExecuteScript(aScriptProto);
 
         // Ignore return value from execution, and don't block
         *aBlock = PR_FALSE;
@@ -3282,12 +3282,17 @@ nsXULDocument::LoadScript(nsXULPrototypeScript* aScriptProto, PRBool* aBlock)
     PRBool useXULCache;
     gXULCache->GetEnabled(&useXULCache);
 
-    if (useXULCache) {
+    if (useXULCache && mScriptGlobalObject) {
+        // XUL cache only handle JS currently.
         gXULCache->GetScript(aScriptProto->mSrcURI,
-                             NS_REINTERPRET_CAST(void**, &aScriptProto->mJSObject));
+                             &aScriptProto->mScriptObject);
 
-        if (aScriptProto->mJSObject) {
-            rv = ExecuteScript(aScriptProto->mJSObject);
+        if (aScriptProto->mScriptObject) {
+            aScriptProto->mScriptContext = mScriptGlobalObject->GetLanguageContext(
+                                                    nsIProgrammingLanguage::JAVASCRIPT);
+            // failure getting a script context is fatal.
+            NS_ENSURE_TRUE(aScriptProto->mScriptContext != nsnull, NS_ERROR_UNEXPECTED);
+            rv = ExecuteScript(aScriptProto);
 
             // Ignore return value from execution, and don't block
             *aBlock = PR_FALSE;
@@ -3380,7 +3385,7 @@ nsXULDocument::OnStreamComplete(nsIStreamLoader* aLoader,
         // be writing a new FastLoad file.  If we were reading this script
         // from the FastLoad file, XULContentSinkImpl::OpenScript (over in
         // nsXULContentSink.cpp) would have already deserialized a non-null
-        // script->mJSObject, causing control flow at the top of LoadScript
+        // script->mScriptObject, causing control flow at the top of LoadScript
         // not to reach here.
         nsCOMPtr<nsIURI> uri = scriptProto->mSrcURI;
 
@@ -3394,8 +3399,8 @@ nsXULDocument::OnStreamComplete(nsIStreamLoader* aLoader,
                                     1, this, mCurrentPrototype);
 
         aStatus = rv;
-        if (NS_SUCCEEDED(rv) && scriptProto->mJSObject) {
-            rv = ExecuteScript(scriptProto->mJSObject);
+        if (NS_SUCCEEDED(rv) && scriptProto->mScriptContext) {
+            rv = ExecuteScript(scriptProto);
 
             // If the XUL cache is enabled, save the script object there in
             // case different XUL documents source the same script.
@@ -3421,9 +3426,11 @@ nsXULDocument::OnStreamComplete(nsIStreamLoader* aLoader,
             PRBool useXULCache;
             gXULCache->GetEnabled(&useXULCache);
 
-            if (useXULCache && IsChromeURI(mDocumentURI)) {
+            if (useXULCache && IsChromeURI(mDocumentURI) &&
+                scriptProto->mScriptContext &&
+                scriptProto->mScriptContext->GetLanguage() == nsIProgrammingLanguage::JAVASCRIPT) {
                 gXULCache->PutScript(scriptProto->mSrcURI,
-                                     NS_REINTERPRET_CAST(void*, scriptProto->mJSObject));
+                                     scriptProto->mScriptObject);
             }
 
             if (mIsWritingFastLoad && mCurrentPrototype != mMasterPrototype) {
@@ -3445,9 +3452,13 @@ nsXULDocument::OnStreamComplete(nsIStreamLoader* aLoader,
 
                 NS_ASSERTION(global != nsnull, "master prototype w/o global?!");
                 if (global) {
+                    PRUint32 langID = scriptProto->mScriptContext->GetLanguage();
+                    NS_ASSERTION(global->GetLanguageContext(langID) == scriptProto->mScriptContext,
+                                 "Contexts appear confused?");
                     nsIScriptContext *scriptContext = global->GetContext();
                     if (scriptContext)
-                        scriptProto->SerializeOutOfLine(nsnull, scriptContext);
+                        // xxxmarkh - global?
+                        scriptProto->SerializeOutOfLine(nsnull, global);
                 }
             }
         }
@@ -3476,8 +3487,8 @@ nsXULDocument::OnStreamComplete(nsIStreamLoader* aLoader,
         doc->mNextSrcLoadWaiter = nsnull;
 
         // Execute only if we loaded and compiled successfully, then resume
-        if (NS_SUCCEEDED(aStatus) && scriptProto->mJSObject) {
-            doc->ExecuteScript(scriptProto->mJSObject);
+        if (NS_SUCCEEDED(aStatus) && scriptProto->mScriptObject) {
+            doc->ExecuteScript(scriptProto);
         }
         doc->ResumeWalk();
         NS_RELEASE(doc);
@@ -3488,23 +3499,31 @@ nsXULDocument::OnStreamComplete(nsIStreamLoader* aLoader,
 
 
 nsresult
-nsXULDocument::ExecuteScript(JSObject* aScriptObject)
+nsXULDocument::ExecuteScript(nsIScriptContext * aContext, void * aScriptObject)
 {
-    NS_PRECONDITION(aScriptObject != nsnull, "null ptr");
-    if (! aScriptObject)
+    NS_PRECONDITION(aScriptObject != nsnull && aContext != nsnull, "null ptr");
+    if (! aScriptObject || ! aContext)
         return NS_ERROR_NULL_POINTER;
 
     // Execute the precompiled script with the given version
+    nsresult rv;
+    void *global = mScriptGlobalObject->GetLanguageGlobal(aContext->GetLanguage());
+    rv = aContext->ExecuteScript(aScriptObject,
+                                 global,
+                                 nsnull, nsnull);
+
+    return rv;
+}
+
+nsresult
+nsXULDocument::ExecuteScript(nsXULPrototypeScript *aScript)
+{
+    NS_PRECONDITION(aScript != nsnull, "null ptr");
+    NS_ENSURE_TRUE(aScript, NS_ERROR_NULL_POINTER);
+
     nsresult rv = NS_ERROR_UNEXPECTED;
-
-    NS_ASSERTION(mScriptGlobalObject != nsnull, "no script global object");
-
-    nsCOMPtr<nsIScriptContext> context;
-    if (mScriptGlobalObject && (context = mScriptGlobalObject->GetContext()))
-        rv = context->ExecuteScript(aScriptObject,
-                                    mScriptGlobalObject->GetGlobalJSObject(),
-                                    nsnull, nsnull);
-
+    if (aScript->mScriptContext && aScript->mScriptObject)
+        rv = ExecuteScript(aScript->mScriptContext, aScript->mScriptObject);
     return rv;
 }
 
diff --git a/mozilla/content/xul/document/src/nsXULDocument.h b/mozilla/content/xul/document/src/nsXULDocument.h
index 217ff7cacbe..e98c73b600a 100644
--- a/mozilla/content/xul/document/src/nsXULDocument.h
+++ b/mozilla/content/xul/document/src/nsXULDocument.h
@@ -353,7 +353,13 @@ protected:
      * Execute the precompiled script object scoped by this XUL document's
      * containing window object, and using its associated script context.
      */
-    nsresult ExecuteScript(JSObject* aScriptObject);
+    nsresult ExecuteScript(nsIScriptContext *aContext, void* aScriptObject);
+
+    /**
+     * Helper method for the above that uses aScript to find the appropriate
+     * script context and object.
+     */
+    nsresult ExecuteScript(nsXULPrototypeScript *aScript);
 
     /**
      * Create a delegate content model element from a prototype.
diff --git a/mozilla/content/xul/document/src/nsXULPrototypeDocument.cpp b/mozilla/content/xul/document/src/nsXULPrototypeDocument.cpp
index 2833c2148b3..a757f8ee844 100644
--- a/mozilla/content/xul/document/src/nsXULPrototypeDocument.cpp
+++ b/mozilla/content/xul/document/src/nsXULPrototypeDocument.cpp
@@ -54,8 +54,10 @@
 #include "nsIScriptGlobalObjectOwner.h"
 #include "nsIScriptObjectPrincipal.h"
 #include "nsIScriptSecurityManager.h"
+#include "nsILanguageRuntime.h"
 #include "nsIServiceManager.h"
-#include "nsISupportsArray.h"
+#include "nsISupportsArray.h" // deprecated array interface.
+#include "nsIArray.h"         // blessed array interface.
 #include "nsIURI.h"
 #include "nsIXULDocument.h"
 #include "nsIXULPrototypeDocument.h"
@@ -71,6 +73,7 @@
 #include "nsNodeInfoManager.h"
 #include "nsContentUtils.h"
 
+#include "nsDOMJSUtils.h" // for GetScriptContextFromJSContext
 
 static NS_DEFINE_CID(kDOMScriptObjectFactoryCID,
                      NS_DOM_SCRIPT_OBJECT_FACTORY_CID);
@@ -86,8 +89,6 @@ public:
     NS_DECL_ISUPPORTS
 
     // nsIScriptGlobalObject methods
-    virtual void SetContext(nsIScriptContext *aContext);
-    virtual nsIScriptContext *GetContext();
     virtual nsresult SetNewDocument(nsIDOMDocument *aDocument,
                                     nsISupports *aState,
                                     PRBool aRemoveEventListeners,
@@ -102,10 +103,14 @@ public:
                                     nsIDOMEvent** aDOMEvent,
                                     PRUint32 aFlags,
                                     nsEventStatus* aEventStatus);
-    virtual JSObject *GetGlobalJSObject();
-    virtual void OnFinalize(JSObject *aObject);
+    virtual void OnFinalize();
     virtual void SetScriptsEnabled(PRBool aEnabled, PRBool aFireTimeouts);
-    virtual nsresult SetNewArguments(JSObject *aArguments);
+    virtual nsresult SetNewArguments(nsIArray *aArguments);
+
+    virtual nsIScriptContext *GetLanguageContext(PRUint32 lang);
+    virtual void *GetLanguageGlobal(PRUint32 lang);
+  
+    virtual nsresult SetLanguageContext(PRUint32 language, nsIScriptContext *ctx);
 
     // nsIScriptObjectPrincipal methods
     virtual nsIPrincipal* GetPrincipal();
@@ -113,11 +118,11 @@ public:
 protected:
     virtual ~nsXULPDGlobalObject();
 
-    nsCOMPtr<nsIScriptContext> mScriptContext;
-    JSObject *mJSObject;    // XXX JS language rabies bigotry badness
-
     nsIScriptGlobalObjectOwner* mGlobalObjectOwner; // weak reference
 
+    nsCOMPtr<nsIScriptContext>  mLanguageContexts[nsIProgrammingLanguage::MAX];
+    void *                      mLanguageGlobals[nsIProgrammingLanguage::MAX];
+
     static JSClass gSharedGlobalClass;
 };
 
@@ -207,7 +212,10 @@ nsXULPDGlobalObject_finalize(JSContext *cx, JSObject *obj)
     nsCOMPtr<nsIScriptGlobalObject> sgo(do_QueryInterface(nativeThis));
 
     if (sgo) {
-        sgo->OnFinalize(obj);
+        // We previously passed 'obj' to OnFinalize which did this check...
+        NS_ASSERTION(obj == sgo->GetLanguageGlobal(nsIProgrammingLanguage::JAVASCRIPT),
+                     "Finalizing global that doesn't have our global obj");
+        sgo->OnFinalize();
     }
 
     // The addref was part of JSObject construction
@@ -268,7 +276,7 @@ nsXULPrototypeDocument::Init()
 nsXULPrototypeDocument::~nsXULPrototypeDocument()
 {
     if (mGlobalObject) {
-        mGlobalObject->SetContext(nsnull); // remove circular reference
+        mGlobalObject->OnFinalize();
         mGlobalObject->SetGlobalObjectOwner(nsnull); // just in case
     }
     
@@ -406,10 +414,6 @@ nsXULPrototypeDocument::Read(nsIObjectInputStream* aStream)
     if (! mRoot)
        return NS_ERROR_OUT_OF_MEMORY;
 
-    nsIScriptContext *scriptContext = mGlobalObject->GetContext();
-    NS_ASSERTION(scriptContext != nsnull,
-                 "no prototype script context!");
-
     // nsINodeInfo table
     nsCOMArray<nsINodeInfo> nodeInfos;
 
@@ -432,7 +436,7 @@ nsXULPrototypeDocument::Read(nsIObjectInputStream* aStream)
     if ((nsXULPrototypeNode::Type)type != nsXULPrototypeNode::eType_Element)
         return NS_ERROR_FAILURE;
 
-    rv |= mRoot->Deserialize(aStream, scriptContext, mURI, &nodeInfos);
+    rv |= mRoot->Deserialize(aStream, mGlobalObject, mURI, &nodeInfos);
     rv |= NotifyLoadDone();
 
     return rv;
@@ -545,10 +549,8 @@ nsXULPrototypeDocument::Write(nsIObjectOutputStream* aStream)
     nsIScriptGlobalObject* globalObject = GetScriptGlobalObject();
     NS_ENSURE_TRUE(globalObject, NS_ERROR_UNEXPECTED);
 
-    nsIScriptContext *scriptContext = globalObject->GetContext();
-
     if (mRoot)
-        rv |= mRoot->Serialize(aStream, scriptContext, &nodeInfos);
+        rv |= mRoot->Serialize(aStream, globalObject, &nodeInfos);
  
     return rv;
 }
@@ -781,9 +783,9 @@ nsXULPrototypeDocument::GetScriptGlobalObject()
 //
 
 nsXULPDGlobalObject::nsXULPDGlobalObject()
-    : mJSObject(nsnull),
-      mGlobalObjectOwner(nsnull)
+    :  mGlobalObjectOwner(nsnull)
 {
+  memset(mLanguageGlobals, 0, sizeof(mLanguageGlobals));
 }
 
 
@@ -805,43 +807,105 @@ NS_INTERFACE_MAP_END
 // nsIScriptGlobalObject methods
 //
 
-void
-nsXULPDGlobalObject::SetContext(nsIScriptContext *aContext)
+nsresult
+nsXULPDGlobalObject::SetLanguageContext(PRUint32 lang_id, nsIScriptContext *aScriptContext)
 {
-    mScriptContext = aContext;
+  // almost a clone of nsGlobalWindow
+  nsresult rv;
+
+  PRBool ok = lang_id > nsIProgrammingLanguage::UNKNOWN && lang_id <= nsIProgrammingLanguage::MAX;
+  NS_ASSERTION(ok, "Invalid programming language ID requested");
+  NS_ENSURE_TRUE(ok, NS_ERROR_INVALID_ARG);
+  PRUint32 lang_ndx = lang_id - 1;
+
+  if (!aScriptContext)
+    NS_WARNING("Possibly early removal of script object, see bug #41608");
+  else {
+    // should probably assert the context is clean???
+    aScriptContext->WillInitializeContext();
+    // NOTE: We init this context with a NULL global - this is subtly
+    // different than nsGlobalWindow which passes 'this'
+    rv = aScriptContext->InitContext(nsnull);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  nsIScriptContext *existing;
+  existing = mLanguageContexts[lang_ndx];
+  NS_ASSERTION(!aScriptContext || !existing, "Bad call to SetContext()!");
+
+  if (existing)
+    existing->SetOwner(nsnull);
+  void *script_glob = nsnull;
+
+  if (aScriptContext) {
+    aScriptContext->DidInitializeContext();
+    script_glob = aScriptContext->GetNativeGlobal();
+    NS_ASSERTION(script_glob, "GetNativeGlobal returned NULL!");
+  }
+  mLanguageContexts[lang_ndx] = aScriptContext;
+  mLanguageGlobals[lang_ndx] = script_glob;
+  return NS_OK;
 }
 
-
 nsIScriptContext *
-nsXULPDGlobalObject::GetContext()
+nsXULPDGlobalObject::GetLanguageContext(PRUint32 lang_id)
 {
-    // This whole fragile mess is predicated on the fact that
-    // GetContext() will be called before GetScriptObject() is.
-    if (! mScriptContext) {
-        nsCOMPtr<nsIDOMScriptObjectFactory> factory =
-            do_GetService(kDOMScriptObjectFactoryCID);
-        NS_ENSURE_TRUE(factory, nsnull);
+  // All languages are stored in table, indexed by language-1
+  PRBool ok = lang_id > nsIProgrammingLanguage::UNKNOWN && lang_id <= nsIProgrammingLanguage::MAX;
+  NS_ASSERTION(ok, "Invalid programming language ID requested");
+  NS_ENSURE_TRUE(ok, nsnull);
+  PRUint32 lang_ndx = lang_id - 1;
+  
+  // This global object creates a context on demand - do that now.
+  if (mLanguageContexts[lang_ndx] == nsnull) {
+    nsresult rv;
+    NS_ASSERTION(mLanguageGlobals[lang_ndx] == nsnull, "Have global without context?");
 
-        nsresult rv =
-            factory->NewScriptContext(nsnull, getter_AddRefs(mScriptContext));
-        if (NS_FAILED(rv))
-            return nsnull;
+    nsCOMPtr<nsIDOMScriptObjectFactory> factory = do_GetService(kDOMScriptObjectFactoryCID);
+    NS_ENSURE_TRUE(factory, nsnull);
+    nsCOMPtr<nsILanguageRuntime> languageRuntime;
+    rv = factory->GetLanguageRuntimeByID(lang_id, getter_AddRefs(languageRuntime));
+    NS_ENSURE_SUCCESS(rv, nsnull);
 
-        JSContext *cx = (JSContext *)mScriptContext->GetNativeContext();
+    nsCOMPtr<nsIScriptContext> ctxNew;
+    rv = languageRuntime->CreateContext(getter_AddRefs(ctxNew));
+    // For JS, we have to setup a special global object.  We do this then
+    // attach it as the global for this context.  Then, ::SetLanguageContext
+    // will re-fetch the global and set it up in our language globals array.
+    if (lang_id == nsIProgrammingLanguage::JAVASCRIPT) {
+      // some special JS specific code we should abstract
+      JSContext *cx = (JSContext *)ctxNew->GetNativeContext();
+      JSObject *newGlob = ::JS_NewObject(cx, &gSharedGlobalClass, nsnull, nsnull);
+      if (!newGlob)
+        return nsnull;
 
-        mJSObject = ::JS_NewObject(cx, &gSharedGlobalClass, nsnull, nsnull);
-        if (!mJSObject)
-            return nsnull;
+      ::JS_SetGlobalObject(cx, newGlob);
 
-        ::JS_SetGlobalObject(cx, mJSObject);
-
-        // Add an owning reference from JS back to us. This'll be
-        // released when the JSObject is finalized.
-        ::JS_SetPrivate(cx, mJSObject, this);
-        NS_ADDREF(this);
+      // Add an owning reference from JS back to us. This'll be
+      // released when the JSObject is finalized.
+      ::JS_SetPrivate(cx, newGlob, this);
+      // What is this addref for?
+      NS_ADDREF(this);
     }
 
-    return mScriptContext;
+    NS_ENSURE_SUCCESS(rv, nsnull);
+    rv = SetLanguageContext(lang_id, ctxNew);
+    NS_ENSURE_SUCCESS(rv, nsnull);
+  }
+  return mLanguageContexts[lang_ndx];
+}
+
+void *
+nsXULPDGlobalObject::GetLanguageGlobal(PRUint32 lang_id)
+{
+  // All languages are stored in table, indexed by language-1
+  PRBool ok = lang_id > nsIProgrammingLanguage::UNKNOWN && lang_id <= nsIProgrammingLanguage::MAX;
+  NS_ASSERTION(ok, "Invalid programming language ID requested");
+  NS_ENSURE_TRUE(ok, nsnull);
+  PRUint32 lang_ndx = lang_id - 1;
+
+  NS_ASSERTION(mLanguageContexts[lang_ndx] != nsnull, "Querying for global before setting up context?");
+  return mLanguageGlobals[lang_ndx];
 }
 
 
@@ -904,29 +968,18 @@ nsXULPDGlobalObject::HandleDOMEvent(nsPresContext* aPresContext,
     return NS_ERROR_UNEXPECTED;
 }
 
-JSObject *
-nsXULPDGlobalObject::GetGlobalJSObject()
-{
-    // The prototype document has its own special secret script object
-    // that can be used to compile scripts and event handlers.
-
-    if (!mScriptContext)
-        return nsnull;
-
-    JSContext* cx = NS_REINTERPRET_CAST(JSContext*,
-                                        mScriptContext->GetNativeContext());
-    if (!cx)
-        return nsnull;
-
-    return ::JS_GetGlobalObject(cx);
-}
-
 void
-nsXULPDGlobalObject::OnFinalize(JSObject *aObject)
+nsXULPDGlobalObject::OnFinalize()
 {
-    NS_ASSERTION(aObject == mJSObject, "Wrong object finalized!");
-
-    mJSObject = nsnull;
+  for (PRUint32 lang_ndx=0;lang_ndx < nsIProgrammingLanguage::MAX; lang_ndx++) {
+    if (mLanguageContexts[lang_ndx])
+      mLanguageContexts[lang_ndx]->FinalizeClasses(mLanguageGlobals[lang_ndx]);
+    else
+      NS_ASSERTION(mLanguageGlobals[lang_ndx] == nsnull,
+                   "OnFinalize has a global without matching context!");
+    mLanguageContexts[lang_ndx] = nsnull;
+    mLanguageGlobals[lang_ndx] = nsnull;
+  }
 }
 
 void
@@ -936,7 +989,7 @@ nsXULPDGlobalObject::SetScriptsEnabled(PRBool aEnabled, PRBool aFireTimeouts)
 }
 
 nsresult
-nsXULPDGlobalObject::SetNewArguments(JSObject *aArguments)
+nsXULPDGlobalObject::SetNewArguments(nsIArray *aArguments)
 {
     NS_NOTREACHED("waaah!");
     return NS_ERROR_UNEXPECTED;
diff --git a/mozilla/docshell/base/nsDocShell.cpp b/mozilla/docshell/base/nsDocShell.cpp
index 59efb574398..cc6c367506a 100644
--- a/mozilla/docshell/base/nsDocShell.cpp
+++ b/mozilla/docshell/base/nsDocShell.cpp
@@ -76,6 +76,7 @@
 #include "nsIScriptSecurityManager.h"
 #include "nsIJSContextStack.h"
 #include "nsIScriptObjectPrincipal.h"
+#include "nsILanguageRuntime.h"
 #include "nsDocumentCharsetInfoCID.h"
 #include "nsICanvasFrame.h"
 #include "nsIScrollableFrame.h"
@@ -86,6 +87,8 @@
 #include "nsAutoPtr.h"
 #include "nsIPrefService.h"
 #include "nsIWritablePropertyBag2.h"
+#include "nsIProgrammingLanguage.h"
+#include "nsDOMJSUtils.h" // GetScriptContextFromJSContext
 
 // we want to explore making the document own the load group
 // so we can associate the document URI with the load group.
@@ -8068,9 +8071,20 @@ nsDocShell::EnsureScriptEnvironment()
         SetGlobalObjectOwner(NS_STATIC_CAST
                              (nsIScriptGlobalObjectOwner *, this));
 
+    // Ensure the script object is set to run javascript - other languages
+    // setup on demand.
+    nsresult rv;
+    nsCOMPtr<nsILanguageRuntime> languageRuntime;
+    rv = factory->GetLanguageRuntimeByID(nsIProgrammingLanguage::JAVASCRIPT,
+                                         getter_AddRefs(languageRuntime));
+    NS_ENSURE_SUCCESS(rv, rv);
+
     nsCOMPtr<nsIScriptContext> context;
-    factory->NewScriptContext(mScriptGlobal, getter_AddRefs(context));
-    NS_ENSURE_TRUE(context, NS_ERROR_FAILURE);
+    rv = languageRuntime->CreateContext(getter_AddRefs(context));
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = mScriptGlobal->SetLanguageContext(nsIProgrammingLanguage::JAVASCRIPT,
+                                           context);
+    NS_ENSURE_SUCCESS(rv, rv);
 
     // Note that mScriptGlobal has taken a reference to the script
     // context, so we don't have to.
diff --git a/mozilla/dom/public/Makefile.in b/mozilla/dom/public/Makefile.in
index 6afc416071f..d84f9b64f7e 100644
--- a/mozilla/dom/public/Makefile.in
+++ b/mozilla/dom/public/Makefile.in
@@ -53,6 +53,7 @@ XPIDLSRCS	= nsIScriptContextOwner.idl \
 
 EXPORTS=nsIScriptContext.h		\
 	nsIJSNativeInitializer.h	\
+	nsILanguageRuntime.h		\
 	nsIScriptObjectOwner.h		\
 	nsIScriptObjectPrincipal.h	\
 	nsIScriptGlobalObject.h		\
@@ -66,6 +67,7 @@ EXPORTS=nsIScriptContext.h		\
 	nsIDOMClassInfo.h		\
 	nsIBaseDOMException.h		\
 	nsDOMString.h			\
+	nsDOMJSUtils.h			\
 	$(NULL)
 
 include $(topsrcdir)/config/rules.mk
diff --git a/mozilla/dom/public/nsDOMJSUtils.h b/mozilla/dom/public/nsDOMJSUtils.h
new file mode 100644
index 00000000000..98813ca596d
--- /dev/null
+++ b/mozilla/dom/public/nsDOMJSUtils.h
@@ -0,0 +1,26 @@
+
+#ifndef nsDOMJSUtils_h__
+#define nsDOMJSUtils_h__
+
+#include "jsapi.h"
+#include "nsIScriptContext.h"
+
+// seems like overkill for just this 1 function - but let's see what else
+// falls out first.
+inline nsIScriptContext *
+GetScriptContextFromJSContext(JSContext *cx)
+{
+  if (!(::JS_GetOptions(cx) & JSOPTION_PRIVATE_IS_NSISUPPORTS)) {
+    return nsnull;
+  }
+
+  nsCOMPtr<nsIScriptContext> scx =
+    do_QueryInterface(NS_STATIC_CAST(nsISupports *,
+                                     ::JS_GetContextPrivate(cx)));
+
+  // This will return a pointer to something that's about to be
+  // released, but that's ok here.
+  return scx;
+}
+
+#endif // nsDOMJSUtils_h__
diff --git a/mozilla/dom/public/nsIDOMScriptObjectFactory.h b/mozilla/dom/public/nsIDOMScriptObjectFactory.h
index c16ffec54a4..2de08728037 100644
--- a/mozilla/dom/public/nsIDOMScriptObjectFactory.h
+++ b/mozilla/dom/public/nsIDOMScriptObjectFactory.h
@@ -42,20 +42,43 @@
 #include "nsIDOMClassInfo.h"
 #include "nsString.h"
 
+// XXX - need a new IID - but should this entire interface be renamed?
 #define NS_IDOM_SCRIPT_OBJECT_FACTORY_IID   \
 { 0xbac2482a, 0x456e, 0x4ea5,               \
   { 0x83, 0xfb, 0x16, 0xe1, 0x24, 0x9c, 0x16, 0x6f } }
 
 class nsIScriptContext;
 class nsIScriptGlobalObject;
+class nsILanguageRuntime;
 class nsIDOMEventListener;
 
 class nsIDOMScriptObjectFactory : public nsISupports {
 public:  
   NS_DEFINE_STATIC_IID_ACCESSOR(NS_IDOM_SCRIPT_OBJECT_FACTORY_IID)
 
-  NS_IMETHOD NewScriptContext(nsIScriptGlobalObject *aGlobal,
-                              nsIScriptContext **aContext) = 0;
+  // Get a script language given its "name" (ie, the mime-type)
+  // See below - we should consider having the JS code still register
+  // as a component (using the simple name 'javascript', for example).
+  // We would still keep the mime-type matching for JS external, but it would
+  // then allow this module to work correctly with JS, and remove the JS
+  // dependency from this interface.
+  // NOTE: Only works for "pluggable" languages - does *not* work for
+  // javascript - the mime-type handling for JS remains external to this for
+  // perf reasons.  If you want javascript, use GetLanguageByID.
+  NS_IMETHOD GetLanguageRuntime(const nsAString &aLanguageName,
+                                nsILanguageRuntime **aLanguage) = 0;
+
+  // Get a script language given its nsIProgrammingLanguage ID.  Note that for
+  // languages other than javascript, the language must have previously been
+  // instantiated via GetScriptLanguage (as we have no way of mapping language
+  // IDs to contract IDs.)
+  NS_IMETHOD GetLanguageRuntimeByID(PRUint32 aLanguageID, 
+                                    nsILanguageRuntime **aLanguage) = 0;
+
+  // Get the ID for a language given its name - but like GetScriptLanguage,
+  // *not* for javascript.
+  NS_IMETHOD GetIDForLanguage(const nsAString &aLanguageName,
+                              PRUint32 *aLanguageID) = 0;
 
   NS_IMETHOD NewScriptGlobalObject(PRBool aIsChrome,
                                    nsIScriptGlobalObject **aGlobal) = 0;
diff --git a/mozilla/dom/public/nsIJSEventListener.h b/mozilla/dom/public/nsIJSEventListener.h
index 134e5f6bea7..69a9bcffa9f 100644
--- a/mozilla/dom/public/nsIJSEventListener.h
+++ b/mozilla/dom/public/nsIJSEventListener.h
@@ -43,7 +43,7 @@
 class nsIScriptObjectOwner;
 class nsIDOMEventListener;
 class nsIAtom;
-struct JSObject;
+class nsIScriptGlobalObject;
 
 #define NS_IJSEVENTLISTENER_IID     \
 { 0xa6cf9118, 0x15b3, 0x11d2,       \
@@ -56,14 +56,18 @@ class nsIJSEventListener : public nsISupports
 public:
   NS_DEFINE_STATIC_IID_ACCESSOR(NS_IJSEVENTLISTENER_IID)
 
-  nsIJSEventListener(nsIScriptContext *aContext, JSObject *aScopeObject,
-                     nsISupports *aTarget)
-    : mContext(aContext), mScopeObject(aScopeObject), mTarget(aTarget)
+  nsIJSEventListener(nsIScriptContext *aContext, nsIScriptGlobalObject *aScopeGlobal,
+                     nsIScriptBinding *aBinding)
+    : mContext(aContext), mScopeGlobal(aScopeGlobal), mBinding(aBinding)
   {
     // mTarget is a weak reference. We are guaranteed because of the
     // ownership model that the target will be freed (and the
     // references dropped) before either the context or the owner goes
     // away.
+    // XXX - eeek - are these lifetimes still OK?  We hold a string reference
+    // to the script binding, which generally holds an indirect reference to
+    // the original target.
+    // XXXMarkh - what to do about the global?  Currently a weakref too.
 
     NS_IF_ADDREF(mContext);
   }
@@ -73,14 +77,14 @@ public:
     return mContext;
   }
 
-  nsISupports *GetEventTarget()
+  nsIScriptBinding *GetEventBinding()
   {
-    return mTarget;
+    return mBinding;
   }
 
-  JSObject *GetEventScope()
+  nsIScriptGlobalObject *GetEventGlobal()
   {
-    return mScopeObject;
+    return mScopeGlobal;
   }
 
   virtual void SetEventName(nsIAtom* aName) = 0;
@@ -88,17 +92,18 @@ public:
 protected:
   ~nsIJSEventListener()
   {
+    // COMPtr??
     NS_IF_RELEASE(mContext);
   }
 
   nsIScriptContext *mContext;
-  JSObject *mScopeObject;
-  nsISupports *mTarget;
+  nsIScriptGlobalObject *mScopeGlobal;
+  nsCOMPtr<nsIScriptBinding> mBinding;
 };
 
 /* factory function */
 nsresult NS_NewJSEventListener(nsIScriptContext *aContext,
-                               JSObject *aScopeObject, nsISupports *aObject,
+                               nsIScriptGlobalObject *aScopeGlobal, nsIScriptBinding *aBinding,
                                nsIDOMEventListener **aReturn);
 
 #endif // nsIJSEventListener_h__
diff --git a/mozilla/dom/public/nsILanguageRuntime.h b/mozilla/dom/public/nsILanguageRuntime.h
new file mode 100644
index 00000000000..bdbab2f8f25
--- /dev/null
+++ b/mozilla/dom/public/nsILanguageRuntime.h
@@ -0,0 +1,79 @@
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is mozilla.org code.
+ *
+ * The Initial Developer of the Original Code is mozilla.org.
+ * Portions created by the Initial Developer are Copyright (C) 2005
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *  Mark Hammond (initial development)
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#ifndef nsILanguageRuntime_h__
+#define nsILanguageRuntime_h__
+
+#include "nsIScriptContext.h"
+
+#define SCRIPT_LANGUAGE_CATEGORY \
+    "script-language"
+
+// {47032A4D-0C22-4125-94B7-864A4B744335}
+#define NS_ISCRIPTLANGUAGEENVIRONMENT_IID \
+{ 0x47032a4d, 0xc22, 0x4125, { 0x94, 0xb7, 0x86, 0x4a, 0x4b, 0x74, 0x43, 0x35 } }
+
+
+/**
+ * A singleton language environment for an application.  Responsible for
+ * initializing and cleaning up the global language environment, and a factory
+ * for language contexts
+ */
+class nsILanguageRuntime : public nsISupports
+{
+public:
+  NS_DEFINE_STATIC_IID_ACCESSOR(NS_ISCRIPTLANGUAGEENVIRONMENT_IID)
+  /*
+   * Return the language ID of this script language
+   */
+  virtual PRUint32 GetLanguage() = 0;
+
+  /*
+   * Called as the language factory is shutting down.
+   */
+  virtual void ShutDown() = 0;
+
+  /* Parses a "version string" for the language into a bit-mask used by
+   * the language implementation.  If the specified version is not supported
+   * an error should be returned.  If the specified version is blank, a default
+   * version should be assumed
+   */
+  virtual nsresult ParseVersion(const nsString &aVersionStr, PRUint32 *verFlags) = 0;
+  
+  /* Factory for a new context for this language */
+  virtual nsresult CreateContext(nsIScriptContext **ret) = 0;
+};
+#endif // nsILanguageRuntime_h__
diff --git a/mozilla/dom/public/nsIScriptContext.h b/mozilla/dom/public/nsIScriptContext.h
index a1fe2a3b246..0b3e7fad453 100644
--- a/mozilla/dom/public/nsIScriptContext.h
+++ b/mozilla/dom/public/nsIScriptContext.h
@@ -42,20 +42,42 @@
 #include "nsString.h"
 #include "nsISupports.h"
 #include "nsCOMPtr.h"
-#include "jsapi.h"
 
 class nsIScriptGlobalObject;
 class nsIScriptSecurityManager;
 class nsIScriptContextOwner;
 class nsIPrincipal;
 class nsIAtom;
+class nsIArray;
 
 typedef void (*nsScriptTerminationFunc)(nsISupports* aRef);
 
+// XXXMarkh - todo - move this to its own file?
+// Better name than "binding"?  Conflicts with BindEventHandler - maybe that
+// could be renamed to AssignEventHandler?
+// 
+#define NS_ISCRIPTBINDING_IID \
+{ /* {2B387445-6955-442f-BB4C-5FED9F7A1736} */ \
+  0x2b387445, 0x6955, 0x442f, \
+   { 0xbb, 0x4c, 0x5f, 0xed, 0x9f, 0x7a, 0x17, 0x36 } }
+
+/**
+ * A binding of an XPCOM object (generally a DOM one) and a namespace for the
+ * object inside script language.
+ */
+class nsIScriptBinding : public nsISupports
+{
+public:
+  NS_DEFINE_STATIC_IID_ACCESSOR(NS_ISCRIPTBINDING_IID)
+  virtual PRUint32 GetLanguage() = 0;
+  virtual void *GetNativeObject() = 0;
+  virtual nsISupports *GetTarget() = 0;
+};
+
 #define NS_ISCRIPTCONTEXT_IID \
-{ /* b3fd8821-b46d-4160-913f-cc8fe8176f5f */ \
-  0xb3fd8821, 0xb46d, 0x4160, \
-  {0x91, 0x3f, 0xcc, 0x8f, 0xe8, 0x17, 0x6f, 0x5f} }
+{ /* {52B46C37-A078-4952-AED7-035D83C810C0} */ \
+  0x52b46c37, 0xa078, 0x4952, \
+  {0xae, 0xd7, 0x3, 0x5d, 0x83, 0xc8, 0x10, 0xc0 } }
 
 /**
  * It is used by the application to initialize a runtime and run scripts.
@@ -69,6 +91,7 @@ class nsIScriptContext : public nsISupports
 public:
   NS_DEFINE_STATIC_IID_ACCESSOR(NS_ISCRIPTCONTEXT_IID)
 
+  virtual PRUint32 GetLanguage() = 0;
   /**
    * Compile and execute a script.
    *
@@ -91,7 +114,7 @@ public:
                                   nsIPrincipal *aPrincipal,
                                   const char *aURL,
                                   PRUint32 aLineNo,
-                                  const char* aVersion,
+                                  PRUint32 aVersion,
                                   nsAString *aRetValue,
                                   PRBool* aIsUndefined) = 0;
 
@@ -100,7 +123,7 @@ public:
                                            nsIPrincipal *aPrincipal,
                                            const char *aURL,
                                            PRUint32 aLineNo,
-                                           const char* aVersion,
+                                           PRUint32 aVersion,
                                            void* aRetValue,
                                            PRBool* aIsUndefined) = 0;
 
@@ -128,7 +151,7 @@ public:
                                  nsIPrincipal* aPrincipal,
                                  const char* aURL,
                                  PRUint32 aLineNo,
-                                 const char* aVersion,
+                                 PRUint32 aVersion,
                                  void** aScriptObject) = 0;
 
   /**
@@ -150,6 +173,15 @@ public:
                                  nsAString* aRetValue,
                                  PRBool* aIsUndefined) = 0;
 
+  /**
+   * Bind a DOM object to the language.
+   */
+  virtual nsresult GetScriptBinding(nsISupports *aObject, void *aScope,
+                                    nsIScriptBinding **aBinding)=0;
+
+  virtual nsresult GetScriptBindingHandler(nsIScriptBinding *aBinding,
+                                           nsString &name,
+                                           void **handler)=0;
   /**
    * Compile the event handler named by atom aName, with function body aBody
    * into a function object returned if ok via *aHandler.  Bind the lowercase
@@ -175,7 +207,7 @@ public:
    *
    * @return NS_OK if the function body was valid and got compiled
    */
-  virtual nsresult CompileEventHandler(void* aTarget,
+  virtual nsresult CompileEventHandler(nsIScriptBinding* aTarget,
                                        nsIAtom* aName,
                                        const char* aEventName,
                                        const nsAString& aBody,
@@ -191,14 +223,11 @@ public:
    * @param aTarget an object telling the scope in which to bind the compiled
    *        event handler function.
    * @param aHandler function object (function and static scope) to invoke.
-   * @param argc actual argument count; length of argv
-   * @param argv vector of arguments; length is argc
-   * @param aBoolResult out parameter returning boolean function result, or
-   *        true if the result was not boolean.
+   * @param argv vector of arguments
+   * @param rval out parameter returning result
    **/
-  virtual nsresult CallEventHandler(JSObject* aTarget, JSObject* aHandler,
-                                    uintN argc, jsval* argv,
-                                    jsval* rval) = 0;
+  virtual nsresult CallEventHandler(nsIScriptBinding* aTarget, void* aHandler,
+                                    nsIArray *argv, nsISupports **rv) = 0;
 
   /**
    * Bind an already-compiled event handler function to a name in the given
@@ -216,7 +245,7 @@ public:
    *        CompileEventHandler
    * @return NS_OK if the function was successfully bound to the name
    */
-  virtual nsresult BindCompiledEventHandler(void* aTarget,
+  virtual nsresult BindCompiledEventHandler(nsIScriptBinding* aTarget,
                                             nsIAtom* aName,
                                             void* aHandler) = 0;
 
@@ -230,13 +259,17 @@ public:
                                    PRBool aShared,
                                    void** aFunctionObject) = 0;
 
-
+  /**
+   *  Inform the context of a GC root
+   */
+  virtual nsresult AddGCRoot(void *object, const char *desc) = 0;
+  virtual nsresult RemoveGCRoot(void *object) = 0;
   /**
    * Set the default scripting language version for this context, which must
    * be a context specific to a particular scripting language.
    *
    **/
-  virtual void SetDefaultLanguageVersion(const char* aVersion) = 0;
+  virtual void SetDefaultLanguageVersion(PRUint32 aVersion) = 0;
 
   /**
    * Return the global object.
@@ -250,6 +283,12 @@ public:
    **/
   virtual void *GetNativeContext() = 0;
 
+  /**
+   * Return the native global object for this context.
+   *
+   **/
+  virtual void *GetNativeGlobal() = 0;
+
   /**
    * Init this context.
    *
@@ -324,6 +363,9 @@ public:
   virtual PRBool GetScriptsEnabled() = 0;
   virtual void SetScriptsEnabled(PRBool aEnabled, PRBool aFireTimeouts) = 0;
 
+  // SetProperty is suspect and jst believes should not be needed.  Currenly
+  // used only for "arguments".
+  virtual nsresult SetProperty(void *aTarget, const char *aPropName, nsISupports *aVal) = 0;
   /** 
    * Called to set/get information if the script context is
    * currently processing a script tag
@@ -342,7 +384,12 @@ public:
    * call DidInitializeContext() when a context is fully
    * (successfully) initialized.
    */
-  virtual nsresult InitClasses(JSObject *aGlobalObj) = 0;
+  virtual nsresult InitClasses(void *aGlobalObj) = 0;
+
+  /**
+   * Finalize script objects on aGlobalObj
+   */
+  virtual nsresult FinalizeClasses(void* aGlobalObj) = 0;
 
   /**
    * Tell the context we're about to be reinitialize it.
@@ -355,21 +402,5 @@ public:
   virtual void DidInitializeContext() = 0;
 };
 
-inline nsIScriptContext *
-GetScriptContextFromJSContext(JSContext *cx)
-{
-  if (!(::JS_GetOptions(cx) & JSOPTION_PRIVATE_IS_NSISUPPORTS)) {
-    return nsnull;
-  }
-
-  nsCOMPtr<nsIScriptContext> scx =
-    do_QueryInterface(NS_STATIC_CAST(nsISupports *,
-                                     ::JS_GetContextPrivate(cx)));
-
-  // This will return a pointer to something that's about to be
-  // released, but that's ok here.
-  return scx;
-}
-
 #endif // nsIScriptContext_h__
 
diff --git a/mozilla/dom/public/nsIScriptGlobalObject.h b/mozilla/dom/public/nsIScriptGlobalObject.h
index 8a9a7aa399f..8fdca5e4757 100644
--- a/mozilla/dom/public/nsIScriptGlobalObject.h
+++ b/mozilla/dom/public/nsIScriptGlobalObject.h
@@ -49,11 +49,13 @@ class nsPresContext;
 class nsIDocShell;
 class nsIDOMWindowInternal;
 class nsIScriptGlobalObjectOwner;
+class nsIArray;
 struct JSObject;
 
+// {6E7EF978-47D0-47c9-9649-CDCDB1E4CCEC}
 #define NS_ISCRIPTGLOBALOBJECT_IID \
-{ 0xd4ddb2f8, 0x385f, 0x4baa, \
-  { 0xba, 0x69, 0x6c, 0x42, 0xb3, 0xc2, 0xd0, 0xd0 } }
+{ 0x6e7ef978, 0x47d0, 0x47c9, \
+{ 0x96, 0x49, 0xcd, 0xcd, 0xb1, 0xe4, 0xcc, 0xec } }
 
 /**
  * The JavaScript specific global object. This often used to store
@@ -65,8 +67,6 @@ class nsIScriptGlobalObject : public nsISupports
 public:
   NS_DEFINE_STATIC_IID_ACCESSOR(NS_ISCRIPTGLOBALOBJECT_IID)
 
-  virtual void SetContext(nsIScriptContext *aContext) = 0;
-  virtual nsIScriptContext *GetContext() = 0;
   virtual nsresult SetNewDocument(nsIDOMDocument *aDocument,
                                   nsISupports *aState,
                                   PRBool aRemoveEventListeners,
@@ -97,13 +97,38 @@ public:
                                   PRUint32 aFlags,
                                   nsEventStatus* aEventStatus)=0;
 
-  virtual JSObject *GetGlobalJSObject() = 0;
+  /**
+   * Get a script context (WITHOUT added reference) for the specified language.
+   */
+  virtual nsIScriptContext *GetLanguageContext(PRUint32 lang) = 0;
+  
+  /**
+   * Get the opaque "global" object for the specified lang.
+   */
+  virtual void *GetLanguageGlobal(PRUint32 lang) = 0;
+
+  // Set/GetContext deprecated methods - use GetLanguageContext/Global
+  virtual JSObject *GetGlobalJSObject() {
+        return (JSObject *)GetLanguageGlobal(nsIProgrammingLanguage::JAVASCRIPT);
+  }
+
+  virtual nsIScriptContext *GetContext() {
+        return GetLanguageContext(nsIProgrammingLanguage::JAVASCRIPT);
+  }
 
   /**
-   * Called when the global JSObject is finalized
+   * Set a new language context for this global.  The native global for the
+   * context is created by the context's GetNativeGlobal() method.
    */
 
-  virtual void OnFinalize(JSObject *aJSObject) = 0;
+  virtual nsresult SetLanguageContext(PRUint32 lang, nsIScriptContext *aContext) = 0;
+
+  /**
+   * Called when the global script is finalized.  Finalizes all contexts and globals
+   * for all languages.
+   */
+
+  virtual void OnFinalize() = 0;
 
   /**
    * Called to enable/disable scripts.
@@ -113,9 +138,10 @@ public:
   /** Set a new arguments object for this window. This will be set on
    * the window right away (if there's an existing document) and it
    * will also be installed on the window when the next document is
-   * loaded.
-   */
-  virtual nsresult SetNewArguments(JSObject *aArguments) = 0;
+   * loaded.  Each language impl is responsible for converting to
+   * an array of args as appropriate for that language.
+    */
+  virtual nsresult SetNewArguments(nsIArray *aArguments) = 0;
 };
 
 #endif
diff --git a/mozilla/dom/public/nsIScriptObjectOwner.h b/mozilla/dom/public/nsIScriptObjectOwner.h
index ba225efee66..c97f05a631d 100644
--- a/mozilla/dom/public/nsIScriptObjectOwner.h
+++ b/mozilla/dom/public/nsIScriptObjectOwner.h
@@ -116,7 +116,7 @@ public:
    * @param aHandler the compiled, bound handler object
    */
   virtual nsresult CompileEventHandler(nsIScriptContext* aContext,
-                                       void* aTarget,
+                                       nsIScriptBinding* aTarget,
                                        nsIAtom *aName,
                                        const nsAString& aBody,
                                        const char* aURL,
diff --git a/mozilla/dom/src/base/nsDOMClassInfo.cpp b/mozilla/dom/src/base/nsDOMClassInfo.cpp
index ddf54ed77bd..2a887321fda 100644
--- a/mozilla/dom/src/base/nsDOMClassInfo.cpp
+++ b/mozilla/dom/src/base/nsDOMClassInfo.cpp
@@ -5784,7 +5784,10 @@ nsWindowSH::Finalize(nsIXPConnectWrappedNative *wrapper, JSContext *cx,
   nsCOMPtr<nsIScriptGlobalObject> sgo(do_QueryWrappedNative(wrapper));
   NS_ENSURE_TRUE(sgo, NS_ERROR_UNEXPECTED);
 
-  sgo->OnFinalize(obj);
+  NS_ASSERTION(obj == sgo->GetLanguageGlobal(nsIProgrammingLanguage::JAVASCRIPT),
+             "Finalizing global that doesn't have our global obj");
+
+  sgo->OnFinalize();
 
   return NS_OK;
 }
@@ -6261,15 +6264,20 @@ nsEventReceiverSH::RegisterCompileHandler(nsIXPConnectWrappedNative *wrapper,
 
   nsresult rv;
 
-  JSObject *scope = GetGlobalJSObject(cx, obj);
-
+  NS_WARNING("Need nsIScriptGlobalObject here, not JSObject - is this ok?");
+  //JSObject *scope = GetGlobalJSObject(cx, obj);
+  nsIScriptGlobalObject *scopeGlobal = script_cx->GetGlobalObject();
   if (compile) {
-    rv = manager->CompileScriptEventListener(script_cx, scope, receiver, atom,
+    // eeek - need a script binding around the receiver.
+    nsCOMPtr<nsIScriptBinding> binding;
+    rv = script_cx->GetScriptBinding(receiver, obj, getter_AddRefs(binding));
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = manager->CompileScriptEventListener(script_cx, scopeGlobal, binding, atom,
                                              did_define);
   } else if (remove) {
     rv = manager->RemoveScriptEventListener(atom);
   } else {
-    rv = manager->RegisterScriptEventListener(script_cx, scope, receiver,
+    rv = manager->RegisterScriptEventListener(script_cx, scopeGlobal, receiver,
                                               atom);
   }
 
diff --git a/mozilla/dom/src/base/nsDOMClassInfo.h b/mozilla/dom/src/base/nsDOMClassInfo.h
index 2ec6d258f64..5e758265412 100644
--- a/mozilla/dom/src/base/nsDOMClassInfo.h
+++ b/mozilla/dom/src/base/nsDOMClassInfo.h
@@ -45,6 +45,7 @@
 #include "jsapi.h"
 #include "nsIScriptSecurityManager.h"
 #include "nsIScriptContext.h"
+#include "nsDOMJSUtils.h" // for GetScriptContextFromJSContext
 
 class nsIDOMWindow;
 class nsIDOMNSHTMLOptionCollection;
diff --git a/mozilla/dom/src/base/nsDOMScriptObjectFactory.cpp b/mozilla/dom/src/base/nsDOMScriptObjectFactory.cpp
index 9177299fb30..80d110a0aac 100644
--- a/mozilla/dom/src/base/nsDOMScriptObjectFactory.cpp
+++ b/mozilla/dom/src/base/nsDOMScriptObjectFactory.cpp
@@ -62,6 +62,7 @@
 #ifdef MOZ_XUL
 #include "nsIXULPrototypeCache.h"
 #endif
+#include "nsICategoryManager.h"
 
 nsDOMScriptObjectFactory::nsDOMScriptObjectFactory()
 {
@@ -82,6 +83,8 @@ nsDOMScriptObjectFactory::nsDOMScriptObjectFactory()
     xs->RegisterExceptionProvider(this, NS_ERROR_MODULE_SVG);
 #endif
   }
+  // And pre-create the javascript language.
+  NS_CreateJSRuntime(getter_AddRefs(mLanguageArray[nsIProgrammingLanguage::JAVASCRIPT-1]));
 }
 
 NS_INTERFACE_MAP_BEGIN(nsDOMScriptObjectFactory)
@@ -95,12 +98,71 @@ NS_INTERFACE_MAP_END
 NS_IMPL_ADDREF(nsDOMScriptObjectFactory)
 NS_IMPL_RELEASE(nsDOMScriptObjectFactory)
 
+NS_IMETHODIMP
+nsDOMScriptObjectFactory::GetLanguageRuntime(const nsAString &aLanguageName,
+                                             nsILanguageRuntime **aLanguage)
+{
+  // For now, we just treat the category manager as a hash-table, looking
+  // up the contract ID each language request.  This never happens for
+  // javascript, so will do for now.
+  nsresult rv;
+  nsCOMPtr<nsICategoryManager> catman =
+        do_GetService(NS_CATEGORYMANAGER_CONTRACTID, &rv);
+
+  nsXPIDLCString cid;
+  rv = catman->GetCategoryEntry(SCRIPT_LANGUAGE_CATEGORY,
+                                NS_LossyConvertUTF16toASCII(aLanguageName).get(),
+                                getter_Copies(cid));
+  if (NS_FAILED(rv)) {
+    NS_WARNING("No script language registered for this mime-type");
+    return NS_ERROR_FACTORY_NOT_REGISTERED;
+  }
+  // Now get the language service.
+  nsCOMPtr<nsILanguageRuntime> lang =
+      do_GetService(cid, &rv);
+  if (NS_FAILED(rv)) {
+    NS_ERROR("Failed to get the script language service");
+    return rv;
+  }
+  // And stash it away in our array for fast lookup by ID.
+  PRUint32 lang_ndx = lang->GetLanguage() - 1;
+  NS_ASSERTION(mLanguageArray[lang_ndx] == nsnull || mLanguageArray[lang_ndx] == lang,
+               "Got a different language for this ID???");
+  mLanguageArray[lang_ndx] = lang;
+  *aLanguage = lang;
+  NS_IF_ADDREF(*aLanguage);
+  return NS_OK;
+}
 
 NS_IMETHODIMP
-nsDOMScriptObjectFactory::NewScriptContext(nsIScriptGlobalObject *aGlobal,
-                                           nsIScriptContext **aContext)
+nsDOMScriptObjectFactory::GetLanguageRuntimeByID(PRUint32 aLanguageID, 
+                                                 nsILanguageRuntime **aLanguage)
 {
-  return NS_CreateScriptContext(aGlobal, aContext);
+  if (aLanguageID == 0 || aLanguageID > nsIProgrammingLanguage::MAX) {
+    NS_WARNING("Unknown script language");
+    return NS_ERROR_UNEXPECTED;
+  }
+  *aLanguage = mLanguageArray[aLanguageID-1];
+  if (!*aLanguage) {
+    NS_WARNING("Failed to load script language");
+    return NS_ERROR_UNEXPECTED;
+  }
+  NS_IF_ADDREF(*aLanguage);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDOMScriptObjectFactory::GetIDForLanguage(const nsAString &aLanguageName,
+                                           PRUint32 *aLang)
+{
+    nsCOMPtr<nsILanguageRuntime> languageRuntime;
+    nsresult rv;
+    rv = GetLanguageRuntime(aLanguageName, getter_AddRefs(languageRuntime));
+    if (NS_FAILED(rv))
+      return rv;
+
+    *aLang = languageRuntime->GetLanguage();
+    return NS_OK;
 }
 
 NS_IMETHODIMP
@@ -180,7 +242,12 @@ nsDOMScriptObjectFactory::Observe(nsISupports *aSubject,
 
     nsGlobalWindow::ShutDown();
     nsDOMClassInfo::ShutDown();
-    nsJSEnvironment::ShutDown();
+
+    for (PRUint32 i=0;i<sizeof(mLanguageArray)/sizeof(mLanguageArray[0]);i++)
+      if (mLanguageArray[i] != nsnull) {
+        mLanguageArray[i]->ShutDown();
+        mLanguageArray[i] = nsnull;
+      }
 
     nsCOMPtr<nsIExceptionService> xs =
       do_GetService(NS_EXCEPTIONSERVICE_CONTRACTID);
diff --git a/mozilla/dom/src/base/nsDOMScriptObjectFactory.h b/mozilla/dom/src/base/nsDOMScriptObjectFactory.h
index b7ec607dbb1..1259c77e489 100644
--- a/mozilla/dom/src/base/nsDOMScriptObjectFactory.h
+++ b/mozilla/dom/src/base/nsDOMScriptObjectFactory.h
@@ -53,6 +53,7 @@
 #include "nsIDOMScriptObjectFactory.h"
 #include "nsIObserver.h"
 #include "nsIExceptionService.h"
+#include "nsILanguageRuntime.h"
 
 class nsDOMScriptObjectFactory : public nsIDOMScriptObjectFactory,
                                  public nsIObserver,
@@ -70,8 +71,14 @@ public:
   NS_DECL_NSIEXCEPTIONPROVIDER
 
   // nsIDOMScriptObjectFactory
-  NS_IMETHOD NewScriptContext(nsIScriptGlobalObject *aGlobal,
-                              nsIScriptContext **aContext);
+  NS_IMETHOD GetLanguageRuntime(const nsAString &aLanguageName,
+                                nsILanguageRuntime **aLanguage);
+
+  NS_IMETHOD GetLanguageRuntimeByID(PRUint32 aLanguageID, 
+                                    nsILanguageRuntime **aLanguage);
+
+  NS_IMETHOD GetIDForLanguage(const nsAString &aLanguageName,
+                              PRUint32 *aLanguageID);
 
   NS_IMETHOD NewScriptGlobalObject(PRBool aIsChrome,
                                    nsIScriptGlobalObject **aGlobal);
@@ -86,4 +93,7 @@ public:
                                   PRUint32 aScriptableFlags,
                                   PRBool aHasClassInterface,
                                   const nsCID *aConstructorCID);
+protected:
+  // Indexed by language_id-1
+  nsCOMPtr<nsILanguageRuntime> mLanguageArray[nsIProgrammingLanguage::MAX-1];
 };
diff --git a/mozilla/dom/src/base/nsGlobalWindow.cpp b/mozilla/dom/src/base/nsGlobalWindow.cpp
index bd05b16134b..b5b14ffe6cc 100644
--- a/mozilla/dom/src/base/nsGlobalWindow.cpp
+++ b/mozilla/dom/src/base/nsGlobalWindow.cpp
@@ -141,6 +141,7 @@
 #include "nsCSSProps.h"
 #include "nsIURIFixup.h"
 #include "nsCDefaultURIFixup.h"
+#include "nsArray.h"
 
 #include "plbase64.h"
 
@@ -260,6 +261,40 @@ static const char kDOMSecurityWarningsBundleURL[] = "chrome://global/locale/dom/
 static const char kCryptoContractID[] = NS_CRYPTO_CONTRACTID;
 static const char kPkcs11ContractID[] = NS_PKCS11_CONTRACTID;
 
+// This is a bit of a hack - used to create a temporary script binding to
+// the global window itself.
+class nsSelfScriptBinding : public nsIScriptBinding {
+public:
+  nsSelfScriptBinding(PRUint32 language, void *scope)
+    : mLanguage(language), mScope(scope) {;}
+    
+  NS_DECL_ISUPPORTS
+
+  virtual PRUint32 GetLanguage() {return mLanguage;}
+  void *GetNativeObject() {return mScope;}
+  nsISupports *GetTarget() {NS_ERROR("Don't have the target!"); return nsnull;}
+protected:
+  void *mScope;
+  PRUint32 mLanguage;
+};
+// nsSelfScriptBinding
+// QueryInterface implementation for nsSelfScriptBinding
+NS_INTERFACE_MAP_BEGIN(nsSelfScriptBinding)
+  NS_INTERFACE_MAP_ENTRY(nsSelfScriptBinding)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_ADDREF(nsSelfScriptBinding)
+NS_IMPL_RELEASE(nsSelfScriptBinding)
+
+nsresult MakeSelfBinding(PRUint32 lang, void *scope, nsIScriptBinding **aResult)
+{
+    *aResult = new nsSelfScriptBinding(lang, scope);
+    if (!*aResult)
+        return NS_ERROR_UNEXPECTED;
+    NS_IF_ADDREF(*aResult);
+    return NS_OK;
+}
+
 
 //*****************************************************************************
 //***    nsGlobalWindow: Object Management
@@ -282,6 +317,7 @@ nsGlobalWindow::nsGlobalWindow(nsGlobalWindow *aOuterWindow)
     mTimeoutFiringDepth(0),
     mJSObject(nsnull)
 {
+  memset(mLanguageGlobals, 0, sizeof(mLanguageGlobals));
   // Initialize the PRCList (this).
   PR_INIT_CLIST(this);
 
@@ -485,37 +521,110 @@ NS_IMPL_RELEASE(nsGlobalWindow)
 // nsGlobalWindow::nsIScriptGlobalObject
 //*****************************************************************************
 
-void
-nsGlobalWindow::SetContext(nsIScriptContext* aContext)
+nsresult
+nsGlobalWindow::SetLanguageContext(PRUint32 lang_id, nsIScriptContext *aScriptContext)
 {
-  NS_ASSERTION(IsOuterWindow(), "Uh, SetContext() called on inner window!");
-  NS_ASSERTION(!aContext || !mContext, "Bad call to SetContext()!");
+  nsresult rv;
+  
+  PRBool ok = lang_id > nsIProgrammingLanguage::UNKNOWN && lang_id <= nsIProgrammingLanguage::MAX;
+  NS_ASSERTION(ok, "Invalid programming language ID requested");
+  NS_ENSURE_TRUE(ok, NS_ERROR_INVALID_ARG);
+  PRUint32 lang_ndx = lang_id - 1;
 
-  // if setting the context to null, then we won't get to clean up the
-  // named reference, so do it now
-  if (!aContext) {
+//  NS_ASSERTION(IsOuterWindow(), "Uh, SetLanguageContext() called on inner window!");
+// XXXmarkh - the above assertion fails when a new language (ie, not JS) is first
+// seen, as we are creating the context.  Therefore we only assert when not the
+// first call for this language on the outer, then forward it to that.
+  if (IsInnerWindow()) {
+    nsGlobalWindow *outer = GetOuterWindowInternal();
+    if (!outer) {
+      NS_WARNING("No outer window available!");
+      return NS_ERROR_FAILURE;
+    }
+    // The outer should assert in this case, but let's do it anyway.
+    NS_ASSERTION(outer->mLanguageContexts[lang_ndx] == nsnull,
+                 "SetLanguageContext on inner window for existing language");
+    return outer->SetLanguageContext(lang_id, aScriptContext);
+  }
+
+
+  if (!aScriptContext)
     NS_WARNING("Possibly early removal of script object, see bug #41608");
-  } else {
-    JSContext *cx = (JSContext *)aContext->GetNativeContext();
-
-    mJSObject = ::JS_GetGlobalObject(cx);
+  else {
+    // should probably assert the context is clean???
+    aScriptContext->WillInitializeContext();
+    // Bind the script context and the global object
+    rv = aScriptContext->InitContext(this);
+    NS_ENSURE_SUCCESS(rv, rv);
   }
 
-  if (mContext) {
-    mContext->SetOwner(nsnull);
-  }
+  nsIScriptContext *existing;
+  existing = mLanguageContexts[lang_ndx];
+  NS_ASSERTION(!aScriptContext || !existing, "Bad call to SetContext()!");
 
-  mContext = aContext;
+  if (existing)
+    existing->SetOwner(nsnull);
+  void *script_glob = nsnull;
 
-  if (mContext) {
+  if (aScriptContext) {
     if (IsFrame()) {
       // This window is a [i]frame, don't bother GC'ing when the
       // frame's context is destroyed since a GC will happen when the
       // frameset or host document is destroyed anyway.
 
-      mContext->SetGCOnDestruction(PR_FALSE);
+      aScriptContext->SetGCOnDestruction(PR_FALSE);
     }
+
+    aScriptContext->DidInitializeContext();
+    script_glob = aScriptContext->GetNativeGlobal();
+    NS_ASSERTION(script_glob, "GetNativeGlobal returned NULL!");
   }
+  // for now, keep mContext real.
+  if (lang_id==nsIProgrammingLanguage::JAVASCRIPT) {
+    mContext = aScriptContext;
+    mJSObject = (JSObject *)script_glob;
+  }
+  mLanguageContexts[lang_ndx] = aScriptContext;
+  mLanguageGlobals[lang_ndx] = script_glob;
+  return NS_OK;
+}
+
+nsIScriptContext *
+nsGlobalWindow::GetLanguageContext(PRUint32 lang)
+{
+  FORWARD_TO_OUTER(GetLanguageContext, (lang), nsnull);
+
+  PRBool ok = lang > nsIProgrammingLanguage::UNKNOWN && lang <= nsIProgrammingLanguage::MAX;
+  NS_ASSERTION(ok, "Invalid programming language ID requested");
+  NS_ENSURE_TRUE(ok, nsnull);
+
+  PRUint32 lang_ndx = lang - 1;
+
+  // for now we are still storing the JS versions in members.
+  if (lang == nsIProgrammingLanguage::JAVASCRIPT) {
+    NS_ASSERTION(mLanguageContexts[lang_ndx] == mContext &&
+                 mLanguageGlobals[lang_ndx] == mJSObject,
+                 "JS language contexts are confused");
+  }
+  return mLanguageContexts[lang_ndx];
+}
+
+void *
+nsGlobalWindow::GetLanguageGlobal(PRUint32 lang)
+{
+  PRBool ok = lang > nsIProgrammingLanguage::UNKNOWN && lang <= nsIProgrammingLanguage::MAX;
+  NS_ASSERTION(ok, "Invalid programming language ID requested");
+  NS_ENSURE_TRUE(ok, nsnull);
+
+  PRUint32 lang_ndx = lang - 1;
+
+  // for now we are still storing the JS versions in members.
+  if (lang == nsIProgrammingLanguage::JAVASCRIPT) {
+    NS_ASSERTION(mLanguageContexts[lang_ndx] == mContext &&
+                 mLanguageGlobals[lang_ndx] == mJSObject,
+                 "JS language contexts are confused");
+  }
+  return mLanguageGlobals[lang_ndx];
 }
 
 nsIScriptContext *
@@ -526,6 +635,13 @@ nsGlobalWindow::GetContext()
   return mContext;
 }
 
+JSObject *
+nsGlobalWindow::GetGlobalJSObject()
+{
+  return mJSObject;
+}
+
+
 PRBool
 nsGlobalWindow::WouldReuseInnerWindow(nsIDocument *aNewDocument)
 {
@@ -1041,6 +1157,8 @@ nsGlobalWindow::SetNewDocument(nsIDOMDocument* aDocument,
         NS_ENSURE_SUCCESS(rv, rv);
 
         mInnerWindowHolder->GetJSObject(&newInnerWindow->mJSObject);
+        // ack - this sucks :(
+        newInnerWindow->mLanguageGlobals[nsIProgrammingLanguage::JAVASCRIPT-1] = newInnerWindow->mJSObject;
       }
 
       if (currentInner && currentInner->mJSObject) {
@@ -1222,12 +1340,7 @@ nsGlobalWindow::SetNewDocument(nsIDOMDocument* aDocument,
       }
 
       if (mArguments) {
-        jsval args = OBJECT_TO_JSVAL(mArguments);
-
-        ::JS_SetProperty(cx, newInnerWindow->mJSObject, "arguments",
-                         &args);
-
-        ::JS_UnlockGCThing(cx, mArguments);
+        newInnerWindow->SetNewArguments(mArguments);
         mArguments = nsnull;
       }
 
@@ -1605,21 +1718,17 @@ nsGlobalWindow::HandleDOMEvent(nsPresContext* aPresContext, nsEvent* aEvent,
   return ret;
 }
 
-JSObject *
-nsGlobalWindow::GetGlobalJSObject()
-{
-  return mJSObject;
-}
-
 void
-nsGlobalWindow::OnFinalize(JSObject *aJSObject)
+nsGlobalWindow::OnFinalize()
 {
-  if (aJSObject == mJSObject) {
-    mJSObject = nsnull;
-  } else if (mJSObject) {
-    NS_ERROR("Huh? XPConnect created more than one wrapper for this global!");
-  } else {
-    NS_WARNING("Weird, we're finalized with a null mJSObject?");
+  for (PRUint32 lang_ndx=0;lang_ndx < nsIProgrammingLanguage::MAX; lang_ndx++) {
+    if (mLanguageContexts[lang_ndx])
+      mLanguageContexts[lang_ndx]->FinalizeClasses(mLanguageGlobals[lang_ndx]);
+    else
+      NS_ASSERTION(mLanguageGlobals[lang_ndx] == nsnull,
+                   "OnFinalize has a global without matching context!");
+    mLanguageContexts[lang_ndx] = nsnull;
+    mLanguageGlobals[lang_ndx] = nsnull;
   }
 }
 
@@ -1637,7 +1746,7 @@ nsGlobalWindow::SetScriptsEnabled(PRBool aEnabled, PRBool aFireTimeouts)
 }
 
 nsresult
-nsGlobalWindow::SetNewArguments(JSObject *aArguments)
+nsGlobalWindow::SetNewArguments(nsIArray *aArguments)
 {
   FORWARD_TO_OUTER(SetNewArguments, (aArguments), NS_ERROR_NOT_INITIALIZED);
 
@@ -1649,17 +1758,17 @@ nsGlobalWindow::SetNewArguments(JSObject *aArguments)
   nsGlobalWindow *currentInner = GetCurrentInnerWindowInternal();
 
   jsval args = OBJECT_TO_JSVAL(aArguments);
+  nsresult rv;
 
+  // todo: work out the best way to get this to *all* contexts?
   if (currentInner && currentInner->mJSObject) {
-    if (!::JS_SetProperty(cx, currentInner->mJSObject, "arguments", &args)) {
-      return NS_ERROR_FAILURE;
-    }
+    rv = mContext->SetProperty(currentInner->mJSObject, "arguments", aArguments);
+    NS_ENSURE_SUCCESS(rv, rv);
   }
 
   // Hold on to the arguments so that we can re-set them once the next
   // document is loaded.
   mArguments = aArguments;
-  ::JS_LockGCThing(cx, mArguments);
 
   return NS_OK;
 }
@@ -4122,7 +4231,7 @@ nsGlobalWindow::Open(const nsAString& aUrl, const nsAString& aName,
     return NS_ERROR_FAILURE; // unlike the public Open method, return an error
   }
 
-  rv = OpenInternal(aUrl, aName, aOptions, PR_FALSE, nsnull, 0, nsnull,
+  rv = OpenInternal(aUrl, aName, aOptions, PR_FALSE, nsnull, nsnull,
                     _retval);
   if (NS_SUCCEEDED(rv)) {
     if (abuseLevel >= openControlled && allowReason != allowSelf) {
@@ -4184,7 +4293,7 @@ nsGlobalWindow::Open(nsIDOMWindow **_retval)
     return NS_OK; // don't open the window, but also don't throw a JS exception
   }
 
-  rv = OpenInternal(url, name, options, PR_FALSE, nsnull, 0, nsnull, _retval);
+  rv = OpenInternal(url, name, options, PR_FALSE, nsnull, nsnull, _retval);
 
   nsCOMPtr<nsIDOMChromeWindow> chrome_win(do_QueryInterface(*_retval));
 
@@ -4231,8 +4340,8 @@ nsGlobalWindow::OpenDialog(const nsAString& aUrl, const nsAString& aName,
                            const nsAString& aOptions,
                            nsISupports* aExtraArgument, nsIDOMWindow** _retval)
 {
-  return OpenInternal(aUrl, aName, aOptions, PR_TRUE, nsnull, 0,
-                      aExtraArgument, _retval);
+  return OpenInternal(aUrl, aName, aOptions, PR_TRUE, nsnull, aExtraArgument,
+                      _retval);
 }
 
 NS_IMETHODIMP
@@ -4260,10 +4369,12 @@ nsGlobalWindow::OpenDialog(nsIDOMWindow** _retval)
   PRUint32 argc;
   jsval *argv = nsnull;
 
+  // XXX - need to get this as nsISupports?
   ncc->GetArgc(&argc);
   ncc->GetArgvPtr(&argv);
 
   if (argc > 0) {
+    NS_ERROR("argv is being ignored!!!!");
     nsJSUtils::ConvertJSValToString(url, cx, argv[0]);
 
     if (argc > 1) {
@@ -4275,7 +4386,7 @@ nsGlobalWindow::OpenDialog(nsIDOMWindow** _retval)
     }
   }
 
-  return OpenInternal(url, name, options, PR_TRUE, argv, argc, nsnull,
+  return OpenInternal(url, name, options, PR_TRUE, nsnull, nsnull,
                       _retval);
 }
 
@@ -5557,11 +5668,11 @@ nsGlobalWindow::GetParentInternal()
 NS_IMETHODIMP
 nsGlobalWindow::OpenInternal(const nsAString& aUrl, const nsAString& aName,
                              const nsAString& aOptions, PRBool aDialog,
-                             jsval *argv, PRUint32 argc,
+                             nsIArray *argv, 
                              nsISupports *aExtraArgument,
                              nsIDOMWindow **aReturn)
 {
-  FORWARD_TO_OUTER(OpenInternal, (aUrl, aName, aOptions, aDialog, argv, argc,
+  FORWARD_TO_OUTER(OpenInternal, (aUrl, aName, aOptions, aDialog, argv,
                                   aExtraArgument, aReturn),
                    NS_ERROR_NOT_INITIALIZED);
 
@@ -5712,12 +5823,29 @@ nsGlobalWindow::OpenInternal(const nsAString& aUrl, const nsAString& aName,
         // dialog is open.
         nsAutoPopupStatePusher popupStatePusher(openAbused, PR_TRUE);
 
+        PRUint32 argc = 0;
+        if (argv)
+            argv->GetLength(&argc);
         if (argc) {
           nsCOMPtr<nsPIWindowWatcher> pwwatch(do_QueryInterface(wwatch));
           if (pwwatch) {
-            PRUint32 extraArgc = argc >= 3 ? argc - 3 : 0;
+            // Remove the first 3 args here - not too sure why.  Create temp argv
+            // surely there is a better way to go!  Apparently no "Clone" method
+            // like nsISupportsArray?
+            nsCOMPtr<nsIMutableArray> tempargv;
+            rv = NS_NewArray(getter_AddRefs(tempargv));
+            NS_ENSURE_SUCCESS(rv, rv);
+            NS_ENSURE_TRUE(tempargv != nsnull, NS_ERROR_OUT_OF_MEMORY);
+            unsigned long i;
+            for (i=3;i<argc;i++) {
+                nsCOMPtr<nsISupports> arg;
+                rv = argv->QueryElementAt(i, NS_GET_IID(nsISupports), getter_AddRefs(arg));
+                NS_ENSURE_SUCCESS(rv, rv);
+                rv = tempargv->AppendElement(arg, PR_FALSE);
+                NS_ENSURE_SUCCESS(rv, rv);
+            }
             rv = pwwatch->OpenWindowJS(this, url.get(), name_ptr, options_ptr,
-                                       aDialog, extraArgc, argv + 3,
+                                       aDialog, tempargv,
                                        getter_AddRefs(domReturn));
           } else {
             NS_ERROR("WindowWatcher service not a nsPIWindowWatcher!");
@@ -5725,6 +5853,8 @@ nsGlobalWindow::OpenInternal(const nsAString& aUrl, const nsAString& aName,
             rv = NS_ERROR_UNEXPECTED;
           }
         } else {
+          // eeek - aExtraArgument needs work
+          NS_ERROR("aExtraArgument not being handled");
           rv = wwatch->OpenWindow(this, url.get(), name_ptr, options_ptr,
                                   aExtraArgument, getter_AddRefs(domReturn));
         }
@@ -5940,7 +6070,7 @@ nsGlobalWindow::SetTimeoutOrInterval(PRBool aIsInterval, PRInt32 *aReturn)
     }
   }
 
-  timeout->mVersion = ::JS_VersionToString(::JS_GetVersion(cx));
+  timeout->mVersion = ::JS_GetVersion(cx);
 
   // Get principal of currently executing code, save for execution of timeout
 
@@ -6162,7 +6292,8 @@ nsGlobalWindow::RunTimeout(nsTimeout *aTimeout)
                             ::JS_GetStringChars(timeout->mExpr));
 
       PRBool is_undefined;
-      scx->EvaluateString(nsDependentString(script), mJSObject,
+      scx->EvaluateString(nsDependentString(script),
+                          GetLanguageGlobal(nsIProgrammingLanguage::JAVASCRIPT),
                           timeout->mPrincipal, timeout->mFileName,
                           timeout->mLineNo, timeout->mVersion, nsnull,
                           &is_undefined);
@@ -6173,9 +6304,20 @@ nsGlobalWindow::RunTimeout(nsTimeout *aTimeout)
         PR_IntervalToMilliseconds(now - timeout->mWhen);
       timeout->mArgv[timeout->mArgc] = INT_TO_JSVAL((jsint) lateness);
 
-      jsval dummy;
-      scx->CallEventHandler(mJSObject, timeout->mFunObj, timeout->mArgc + 1,
-                            timeout->mArgv, &dummy);
+      nsCOMPtr<nsISupports> dummy;
+      // Fix nsISupports -> argv
+      NS_ASSERTION(timeout->mArgc == 0, "Event firing ignoring args");
+      nsCOMPtr<nsIDOMWindow> me =
+            do_QueryInterface(NS_STATIC_CAST(nsIDOMWindow *, this));
+
+      nsCOMPtr<nsIScriptBinding> binding;
+      PRUint32 lang = scx->GetLanguage();
+      // XXXmarkh - is this really necessary?  Could we call
+      // nsIScriptContext->GetScriptBinding(this)?
+      if (NS_SUCCEEDED(MakeSelfBinding(lang, GetLanguageGlobal(lang),
+                                       getter_AddRefs(binding)))) {
+        scx->CallEventHandler(binding, timeout->mFunObj, nsnull, getter_AddRefs(dummy));
+      }
     }
 
     --mTimeoutFiringDepth;
diff --git a/mozilla/dom/src/base/nsGlobalWindow.h b/mozilla/dom/src/base/nsGlobalWindow.h
index 9e91d0a327f..709f1f28924 100644
--- a/mozilla/dom/src/base/nsGlobalWindow.h
+++ b/mozilla/dom/src/base/nsGlobalWindow.h
@@ -109,6 +109,7 @@ class nsScreen;
 class nsHistory;
 class nsIDocShellLoadInfo;
 class WindowStateHolder;
+class nsIArray;
 
 //*****************************************************************************
 // nsGlobalWindow: Global Object for Scripting
@@ -151,8 +152,16 @@ public:
   NS_DECL_ISUPPORTS
 
   // nsIScriptGlobalObject
-  virtual void SetContext(nsIScriptContext *aContext);
   virtual nsIScriptContext *GetContext();
+  virtual JSObject *GetGlobalJSObject();
+
+  virtual nsIScriptContext *GetLanguageContext(PRUint32 lang);
+  virtual void *GetLanguageGlobal(PRUint32 lang);
+
+  // Set a new language context for this global.  The native global for the
+  // context is created by the context's GetNativeGlobal() method.
+  virtual nsresult SetLanguageContext(PRUint32 lang, nsIScriptContext *aContext);
+  
   virtual nsresult SetNewDocument(nsIDOMDocument *aDocument,
                                   nsISupports *aState,
                                   PRBool aRemoveEventListeners,
@@ -166,10 +175,9 @@ public:
                                   nsEvent* aEvent, nsIDOMEvent** aDOMEvent,
                                   PRUint32 aFlags,
                                   nsEventStatus* aEventStatus);
-  virtual JSObject *GetGlobalJSObject();
-  virtual void OnFinalize(JSObject *aJSObject);
+  virtual void OnFinalize();
   virtual void SetScriptsEnabled(PRBool aEnabled, PRBool aFireTimeouts);
-  virtual nsresult SetNewArguments(JSObject *aArguments);
+  virtual nsresult SetNewArguments(nsIArray *aArguments);
 
   // nsIScriptObjectPrincipal
   virtual nsIPrincipal* GetPrincipal();
@@ -324,7 +332,7 @@ protected:
   NS_IMETHOD OpenInternal(const nsAString& aUrl,
                           const nsAString& aName,
                           const nsAString& aOptions,
-                          PRBool aDialog, jsval *argv, PRUint32 argc,
+                          PRBool aDialog, nsIArray *argv,
                           nsISupports *aExtraArgument, nsIDOMWindow **aReturn);
   static void CloseWindow(nsISupports* aWindow);
   static void ClearWindowScope(nsISupports* aWindow);
@@ -432,7 +440,7 @@ protected:
   nsCOMPtr<nsIScriptContext>    mContext;
   nsCOMPtr<nsIDOMWindowInternal> mOpener;
   nsCOMPtr<nsIControllers>      mControllers;
-  JSObject*                     mArguments;
+  nsCOMPtr<nsIArray>            mArguments;
   nsRefPtr<nsNavigator>         mNavigator;
   nsRefPtr<nsScreen>            mScreen;
   nsRefPtr<nsHistory>           mHistory;
@@ -447,6 +455,9 @@ protected:
   nsRefPtr<nsLocation>          mLocation;
   nsString                      mStatus;
   nsString                      mDefaultStatus;
+  // index 0->language_id 1, so index MAX-1 == language_id MAX
+  nsCOMPtr<nsIScriptContext>    mLanguageContexts[nsIProgrammingLanguage::MAX];
+  void *                        mLanguageGlobals[nsIProgrammingLanguage::MAX];
 
   nsIScriptGlobalObjectOwner*   mGlobalObjectOwner; // Weak Reference
   nsIDocShell*                  mDocShell;  // Weak Reference
@@ -568,7 +579,7 @@ struct nsTimeout
   // caller of setTimeout()
   char *mFileName;
   PRUint32 mLineNo;
-  const char *mVersion;
+  PRUint32 mVersion;
 
   // stack depth at which timeout is firing
   PRUint32 mFiringDepth;
diff --git a/mozilla/dom/src/base/nsJSEnvironment.cpp b/mozilla/dom/src/base/nsJSEnvironment.cpp
index ba5123be08c..89f4716aa95 100644
--- a/mozilla/dom/src/base/nsJSEnvironment.cpp
+++ b/mozilla/dom/src/base/nsJSEnvironment.cpp
@@ -59,6 +59,7 @@
 #include "nsIJSContextStack.h"
 #include "nsIJSRuntimeService.h"
 #include "nsCOMPtr.h"
+#include "nsISupportsPrimitives.h"
 #include "nsReadableUtils.h"
 #include "nsJSUtils.h"
 #include "nsIDocShell.h"
@@ -78,6 +79,7 @@
 #include "nsIAtom.h"
 #include "nsContentUtils.h"
 #include "jscntxt.h"
+#include "nsIArray.h"
 
 // For locale aware string methods
 #include "plstr.h"
@@ -132,7 +134,7 @@ static PRBool sReadyForGC;
 nsScriptNameSpaceManager *gNameSpaceManager;
 
 static nsIJSRuntimeService *sRuntimeService;
-JSRuntime *nsJSEnvironment::sRuntime;
+JSRuntime *nsJSRuntime::sRuntime;
 
 static const char kJSRuntimeServiceContractID[] =
   "@mozilla.org/js/xpc/RuntimeService;1";
@@ -157,6 +159,38 @@ static nsICollation *gCollation;
 
 static nsIUnicodeDecoder *gDecoder;
 
+/****************************************************************
+ ************************** AutoFree ****************************
+ ****************************************************************/
+
+class AutoFree {
+public:
+  AutoFree(void *aPtr) : mPtr(aPtr) {
+  }
+  ~AutoFree() {
+    if (mPtr)
+      nsMemory::Free(mPtr);
+  }
+  void Invalidate() {
+    mPtr = 0;
+  }
+private:
+  void *mPtr;
+};
+
+class AutoFreeJSStack {
+public:
+  AutoFreeJSStack(JSContext *ctx, void *aPtr) : mContext(ctx), mStack(aPtr) {
+  }
+  ~AutoFreeJSStack() {
+    if (mContext && mStack)
+      js_FreeStack(mContext, mStack);
+  }
+private:
+  void *mStack;
+  JSContext *mContext;
+};
+
 void JS_DLL_CALLBACK
 NS_ScriptErrorReporter(JSContext *cx,
                        const char *message,
@@ -776,7 +810,7 @@ nsJSContext::EvaluateStringWithValue(const nsAString& aScript,
                                      nsIPrincipal *aPrincipal,
                                      const char *aURL,
                                      PRUint32 aLineNo,
-                                     const char* aVersion,
+                                     PRUint32 aVersion,
                                      void* aRetValue,
                                      PRBool* aIsUndefined)
 {
@@ -795,7 +829,7 @@ nsJSContext::EvaluateStringWithValue(const nsAString& aScript,
   nsresult rv;
   if (!aScopeObject)
     aScopeObject = ::JS_GetGlobalObject(mContext);
-
+  
   // Safety first: get an object representing the script's principals, i.e.,
   // the entities who signed this script, or the fully-qualified-domain-name
   // or "codebase" from which it was loaded.
@@ -850,14 +884,12 @@ nsJSContext::EvaluateStringWithValue(const nsAString& aScript,
     // SecurityManager said "ok", but don't execute if aVersion is specified
     // and unknown.  Do execute with the default version (and avoid thrashing
     // the context's version) if aVersion is not specified.
-    ok = (!aVersion ||
-          (newVersion = ::JS_StringToVersion(aVersion)) != JSVERSION_UNKNOWN);
-    if (ok) {
-      JSVersion oldVersion = JSVERSION_UNKNOWN;
+    // XXX - is this correct - see above.
+    JSVersion oldVersion = JSVERSION_UNKNOWN;
+    if (aVersion != JSVERSION_UNKNOWN)
+        oldVersion = ::JS_SetVersion(mContext, (JSVersion)aVersion);
 
-      if (aVersion)
-        oldVersion = ::JS_SetVersion(mContext, newVersion);
-      ok = ::JS_EvaluateUCScriptForPrincipals(mContext,
+    ok = ::JS_EvaluateUCScriptForPrincipals(mContext,
                                               (JSObject *)aScopeObject,
                                               jsprin,
                                               (jschar*)PromiseFlatString(aScript).get(),
@@ -866,17 +898,16 @@ nsJSContext::EvaluateStringWithValue(const nsAString& aScript,
                                               aLineNo,
                                               &val);
 
-      if (aVersion) {
+    if (oldVersion != JSVERSION_UNKNOWN) {
         ::JS_SetVersion(mContext, oldVersion);
-      }
+    }
 
-      if (!ok) {
+    if (!ok) {
         // Tell XPConnect about any pending exceptions. This is needed
         // to avoid dropping JS exceptions in case we got here through
         // nested calls through XPConnect.
 
         nsContentUtils::NotifyXPCIfExceptionPending(mContext);
-      }
     }
   }
 
@@ -974,7 +1005,7 @@ nsJSContext::EvaluateString(const nsAString& aScript,
                             nsIPrincipal *aPrincipal,
                             const char *aURL,
                             PRUint32 aLineNo,
-                            const char* aVersion,
+                            PRUint32 aVersion,
                             nsAString *aRetValue,
                             PRBool* aIsUndefined)
 {
@@ -1042,19 +1073,15 @@ nsJSContext::EvaluateString(const nsAString& aScript,
 
   nsJSContext::TerminationFuncHolder holder(this);
   if (ok) {
-    JSVersion newVersion = JSVERSION_UNKNOWN;
-
     // SecurityManager said "ok", but don't execute if aVersion is specified
     // and unknown.  Do execute with the default version (and avoid thrashing
     // the context's version) if aVersion is not specified.
-    ok = (!aVersion ||
-          (newVersion = ::JS_StringToVersion(aVersion)) != JSVERSION_UNKNOWN);
-    if (ok) {
-      JSVersion oldVersion = JSVERSION_UNKNOWN;
-
-      if (aVersion)
-        oldVersion = ::JS_SetVersion(mContext, newVersion);
-      ok = ::JS_EvaluateUCScriptForPrincipals(mContext,
+    // XXX - markh isn't sure what needs to be checked here.
+    JSVersion oldVersion = JSVERSION_UNKNOWN;
+    if (aVersion != JSVERSION_UNKNOWN)
+        oldVersion = ::JS_SetVersion(mContext, (JSVersion)aVersion);
+    
+    ok = ::JS_EvaluateUCScriptForPrincipals(mContext,
                                               (JSObject *)aScopeObject,
                                               jsprin,
                                               (jschar*)PromiseFlatString(aScript).get(),
@@ -1063,17 +1090,16 @@ nsJSContext::EvaluateString(const nsAString& aScript,
                                               aLineNo,
                                               &val);
 
-      if (aVersion) {
+    if (oldVersion != JSVERSION_UNKNOWN) {
         ::JS_SetVersion(mContext, oldVersion);
       }
 
-      if (!ok) {
+    if (!ok) {
         // Tell XPConnect about any pending exceptions. This is needed
         // to avoid dropping JS exceptions in case we got here through
         // nested calls through XPConnect.
 
         nsContentUtils::NotifyXPCIfExceptionPending(mContext);
-      }
     }
   }
 
@@ -1111,7 +1137,7 @@ nsJSContext::CompileScript(const PRUnichar* aText,
                            nsIPrincipal *aPrincipal,
                            const char *aURL,
                            PRUint32 aLineNo,
-                           const char* aVersion,
+                           PRUint32 aVersion,
                            void** aScriptObject)
 {
   NS_ENSURE_TRUE(mIsInitialized, NS_ERROR_NOT_INITIALIZED);
@@ -1136,38 +1162,35 @@ nsJSContext::CompileScript(const PRUnichar* aText,
 
   *aScriptObject = nsnull;
   if (ok) {
-    JSVersion newVersion = JSVERSION_UNKNOWN;
-
     // SecurityManager said "ok", but don't compile if aVersion is specified
     // and unknown.  Do compile with the default version (and avoid thrashing
     // the context's version) if aVersion is not specified.
-    if (!aVersion ||
-        (newVersion = ::JS_StringToVersion(aVersion)) != JSVERSION_UNKNOWN) {
-      JSVersion oldVersion = JSVERSION_UNKNOWN;
-      if (aVersion)
-        oldVersion = ::JS_SetVersion(mContext, newVersion);
+    
+    // XXX - markh isn't sure what needs to be checked here.
+    JSVersion oldVersion = JSVERSION_UNKNOWN;
+    if (aVersion != JSVERSION_UNKNOWN)
+        oldVersion = ::JS_SetVersion(mContext, (JSVersion)aVersion);
 
-      JSScript* script =
+    JSScript* script =
         ::JS_CompileUCScriptForPrincipals(mContext,
-                                          (JSObject*) aScopeObject,
+                                          (JSObject *)aScopeObject,
                                           jsprin,
                                           (jschar*) aText,
                                           aTextLength,
                                           aURL,
                                           aLineNo);
-      if (script) {
+    if (script) {
         *aScriptObject = (void*) ::JS_NewScriptObject(mContext, script);
         if (! *aScriptObject) {
           ::JS_DestroyScript(mContext, script);
           script = nsnull;
         }
-      }
-      if (!script)
+    }
+    if (!script)
         rv = NS_ERROR_OUT_OF_MEMORY;
 
-      if (aVersion)
+    if (aVersion != JSVERSION_UNKNOWN)
         ::JS_SetVersion(mContext, oldVersion);
-    }
   }
 
   // Whew!  Finally done with these manually ref-counted things.
@@ -1176,7 +1199,7 @@ nsJSContext::CompileScript(const PRUnichar* aText,
 }
 
 nsresult
-nsJSContext::ExecuteScript(void* aScriptObject,
+nsJSContext::ExecuteScript(void *aScriptObject,
                            void *aScopeObject,
                            nsAString* aRetValue,
                            PRBool* aIsUndefined)
@@ -1217,7 +1240,7 @@ nsJSContext::ExecuteScript(void* aScriptObject,
 
   nsJSContext::TerminationFuncHolder holder(this);
   ok = ::JS_ExecuteScript(mContext,
-                          (JSObject*) aScopeObject,
+                          (JSObject *)aScopeObject,
                           (JSScript*) ::JS_GetPrivate(mContext,
                                                     (JSObject*)aScriptObject),
                           &val);
@@ -1275,7 +1298,7 @@ AtomToEventHandlerName(nsIAtom *aName)
 }
 
 nsresult
-nsJSContext::CompileEventHandler(void *aTarget, nsIAtom *aName,
+nsJSContext::CompileEventHandler(nsIScriptBinding *aTarget, nsIAtom *aName,
                                  const char *aEventName,
                                  const nsAString& aBody,
                                  const char *aURL, PRUint32 aLineNo,
@@ -1290,16 +1313,20 @@ nsJSContext::CompileEventHandler(void *aTarget, nsIAtom *aName,
     return NS_ERROR_UNEXPECTED;
   }
 
-  JSObject *target = (JSObject*)aTarget;
+  JSObject *target = nsnull;
 
   JSPrincipals *jsprin = nsnull;
 
-  if (target) {
+  if (aTarget) {
     // Get the principal of the event target (the object principal),
     // don't get the principal of the global object in this context
     // since that opens up security exploits with delayed event
     // handler compilation on stale DOM objects (objects that live in
     // a document that has already been unloaded).
+    NS_ASSERTION(aTarget->GetLanguage() == nsIProgrammingLanguage::JAVASCRIPT,
+                 "Can't call me with a non js binding!");
+    target = (JSObject *)aTarget->GetNativeObject();
+
     nsCOMPtr<nsIPrincipal> prin;
     nsresult rv = sSecurityManager->GetObjectPrincipal(mContext, target,
                                                        getter_AddRefs(prin));
@@ -1383,20 +1410,25 @@ nsJSContext::CompileFunction(void* aTarget,
 }
 
 nsresult
-nsJSContext::CallEventHandler(JSObject *aTarget, JSObject *aHandler,
-                              uintN argc, jsval *argv, jsval *rval)
+nsJSContext::CallEventHandler(nsIScriptBinding *aTarget, void* aHandler,
+                                    nsIArray *aargv, nsISupports **arv)
 {
   NS_ENSURE_TRUE(mIsInitialized, NS_ERROR_NOT_INITIALIZED);
 
-  *rval = JSVAL_VOID;
-
   if (!mScriptsEnabled) {
     return NS_OK;
   }
 
+  NS_ASSERTION(aTarget->GetLanguage() == nsIProgrammingLanguage::JAVASCRIPT,
+               "Can't call me with a non js binding!");
+  JSObject *target = (JSObject *)aTarget->GetNativeObject();
+  //XXX - fix this!
+  jsval rval_local = JSVAL_VOID;
+  jsval *rval = &rval_local;
+
+  nsresult rv;
   // This one's a lot easier than EvaluateString because we don't have to
   // hassle with principals: they're already compiled into the JS function.
-  nsresult rv;
 
   nsCOMPtr<nsIJSContextStack> stack =
     do_GetService("@mozilla.org/js/xpc/ContextStack;1", &rv);
@@ -1404,14 +1436,24 @@ nsJSContext::CallEventHandler(JSObject *aTarget, JSObject *aHandler,
     return NS_ERROR_FAILURE;
 
   // check if the event handler can be run on the object in question
-  rv = sSecurityManager->CheckFunctionAccess(mContext, aHandler, aTarget);
+  rv = sSecurityManager->CheckFunctionAccess(mContext, aHandler, target);
 
   nsJSContext::TerminationFuncHolder holder(this);
 
   if (NS_SUCCEEDED(rv)) {
+    // Convert args to jsvals.
+    void *mark;
+    PRUint32 argc = 0;
+    jsval *argv = nsnull;
+
+    rv = ConvertSupportsTojsvals(aargv, &argc, &argv, &mark);
+    NS_ENSURE_SUCCESS(rv, rv);
+  
+    AutoFreeJSStack stackGuard(mContext, mark); // ensure always freed.
+
     jsval funval = OBJECT_TO_JSVAL(aHandler);
-    PRBool ok = ::JS_CallFunctionValue(mContext, aTarget, funval, argc, argv,
-                                       rval);
+    PRBool ok = ::JS_CallFunctionValue(mContext, target,
+                                       funval, argc, argv, rval);
 
     if (!ok) {
       // Tell XPConnect about any pending exceptions. This is needed
@@ -1446,20 +1488,21 @@ nsJSContext::CallEventHandler(JSObject *aTarget, JSObject *aHandler,
   if (locked) {
     ::JS_UnlockGCThing(mContext, JSVAL_TO_GCTHING(*rval));
   }
-
   return rv;
 }
 
 nsresult
-nsJSContext::BindCompiledEventHandler(void *aTarget, nsIAtom *aName,
+nsJSContext::BindCompiledEventHandler(nsIScriptBinding *aTarget, nsIAtom *aName,
                                       void *aHandler)
 {
   NS_ENSURE_TRUE(mIsInitialized, NS_ERROR_NOT_INITIALIZED);
+  NS_ASSERTION(aTarget->GetLanguage() == nsIProgrammingLanguage::JAVASCRIPT,
+               "Can't call me with a non js binding!");
 
   const char *charName = AtomToEventHandlerName(aName);
 
   JSObject *funobj = (JSObject*) aHandler;
-  JSObject *target = (JSObject*) aTarget;
+  JSObject *target = (JSObject*) aTarget->GetNativeObject();
 
   nsresult rv;
 
@@ -1492,10 +1535,104 @@ nsJSContext::BindCompiledEventHandler(void *aTarget, nsIAtom *aName,
   return rv;
 }
 
-void
-nsJSContext::SetDefaultLanguageVersion(const char* aVersion)
+nsresult
+nsJSContext::GetScriptBinding(nsISupports *aObject, void *aScope,
+                              nsIScriptBinding **aBinding)
 {
-  ::JS_SetVersion(mContext, ::JS_StringToVersion(aVersion));
+    nsresult rv;
+    nsCOMPtr<nsIXPConnectJSObjectHolder> holder;
+    rv = nsContentUtils::XPConnect()->WrapNative(mContext, (JSObject *)aScope, aObject,
+                                                 NS_GET_IID(nsISupports),
+                                                 getter_AddRefs(holder));
+    *aBinding = new nsJSScriptBinding(holder);
+    if (!*aBinding)
+        return NS_ERROR_OUT_OF_MEMORY;
+    NS_IF_ADDREF(*aBinding);
+    return NS_OK;
+}
+
+nsresult
+nsJSContext::GetScriptBindingHandler(nsIScriptBinding *aBinding,
+                                     nsString &name,
+                                     void **handler)
+{
+  jsval funval;
+  NS_ASSERTION(aBinding->GetLanguage() == nsIProgrammingLanguage::JAVASCRIPT,
+               "Not a js binding!?");
+  if (!JS_LookupUCProperty(mContext, (JSObject *)aBinding->GetNativeObject(),
+                           NS_REINTERPRET_CAST(const jschar *,
+                                               name.get()),
+                           name.Length(), &funval)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  if (JS_TypeOfValue(mContext, funval) != JSTYPE_FUNCTION) {
+    NS_WARNING("ScriptBindingHandler not a function");
+    *handler = nsnull;
+    return NS_OK;
+  }
+  *handler = JSVAL_TO_OBJECT(funval);
+  return NS_OK;
+}
+
+
+// GC root functions lifted from static functions in nsXULElement and still
+// uses the static globals that version did.
+static nsIJSRuntimeService* gJSRuntimeService = nsnull;
+static JSRuntime* gScriptRuntime = nsnull;
+static PRInt32 gScriptRuntimeRefcnt = 0;
+
+nsresult
+nsJSContext::AddGCRoot(void* aScriptObjectRef, const char* aName)
+{
+    if (++gScriptRuntimeRefcnt == 1 || !gScriptRuntime) {
+        CallGetService("@mozilla.org/js/xpc/RuntimeService;1",
+                       &gJSRuntimeService);
+        if (! gJSRuntimeService) {
+            NS_NOTREACHED("couldn't add GC root");
+            return NS_ERROR_FAILURE;
+        }
+
+        gJSRuntimeService->GetRuntime(&gScriptRuntime);
+        if (! gScriptRuntime) {
+            NS_NOTREACHED("couldn't add GC root");
+            return NS_ERROR_FAILURE;
+        }
+    }
+
+    PRBool ok;
+    ok = ::JS_AddNamedRootRT(gScriptRuntime, aScriptObjectRef, aName);
+    if (! ok) {
+        NS_NOTREACHED("couldn't add GC root");
+        return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    return NS_OK;
+}
+
+nsresult
+nsJSContext::RemoveGCRoot(void* aScriptObjectRef)
+{
+    if (! gScriptRuntime) {
+        NS_NOTREACHED("couldn't remove GC root");
+        return NS_ERROR_FAILURE;
+    }
+
+    ::JS_RemoveRootRT(gScriptRuntime, aScriptObjectRef);
+
+    if (--gScriptRuntimeRefcnt == 0) {
+        NS_RELEASE(gJSRuntimeService);
+        gScriptRuntime = nsnull;
+    }
+
+    return NS_OK;
+}
+
+
+void
+nsJSContext::SetDefaultLanguageVersion(PRUint32 aVersion)
+{
+  ::JS_SetVersion(mContext, (JSVersion)aVersion);
 }
 
 nsIScriptGlobalObject *
@@ -1537,6 +1674,12 @@ nsJSContext::GetGlobalObject()
   return sgo;
 }
 
+void *
+nsJSContext::GetNativeGlobal()
+{
+    return ::JS_GetGlobalObject(mContext);
+}
+
 void *
 nsJSContext::GetNativeContext()
 {
@@ -1689,6 +1832,323 @@ nsJSContext::InitializeLiveConnectClasses(JSObject *aGlobalObj)
   return NS_OK;
 }
 
+nsresult
+nsJSContext::SetProperty(void *aTarget, const char *aPropName, nsISupports *aArgs)
+{
+  // eeek - do we need to ::JS_LockGCThing(cx, ...);
+  PRUint32  argc;
+  jsval    *argv = nsnull;
+  void *mark;
+  
+  nsresult rv;
+  rv = ConvertSupportsTojsvals(aArgs, &argc, &argv, &mark);
+  NS_ENSURE_SUCCESS(rv, rv);
+  AutoFreeJSStack stackGuard(mContext, mark); // ensure always freed.
+
+
+  // got the array, now attach it.
+  JSObject *args = ::JS_NewArrayObject(mContext, argc, argv);
+  // this looks suspect!
+  jsval vargs = OBJECT_TO_JSVAL(args);
+
+  rv = ::JS_SetProperty(mContext, NS_REINTERPRET_CAST(JSObject *, aTarget), aPropName, &vargs) ?
+       NS_OK : NS_ERROR_FAILURE;
+  // free 'args'???
+
+  return rv;
+}
+
+nsresult
+nsJSContext::ConvertSupportsTojsvals(nsISupports *aArgs,
+                                     PRUint32 *aArgc, jsval **aArgv,
+                                     void **aMarkp)
+{
+  nsresult rv = NS_OK;
+
+  *aArgv = nsnull;
+  *aArgc = 0;
+  *aMarkp = nsnull;
+
+  // copy the elements in aArgsArray into the JS array
+
+  if (!aArgs)
+    return NS_OK;
+  PRUint32 argCtr, argCount;
+  // XXX - this was copied from window.args handling.  I don't think we
+  // need to handle an array and a simple object here?
+  nsCOMPtr<nsIArray> argsArray(do_QueryInterface(aArgs));
+
+  if (argsArray) {
+    rv = argsArray->GetLength(&argCount);
+    NS_ENSURE_SUCCESS(rv, rv);
+    if (argCount == 0)
+      return NS_OK;
+  } else
+    argCount = 1; // the nsISupports which is not an array
+
+  JSContext           *cx = mContext;
+  NS_ENSURE_TRUE(cx, NS_ERROR_UNEXPECTED);
+
+  jsval *argv = js_AllocStack(cx, argCount, aMarkp);
+  NS_ENSURE_TRUE(argv, NS_ERROR_OUT_OF_MEMORY);
+
+  if (argsArray)
+    for (argCtr = 0; argCtr < argCount && NS_SUCCEEDED(rv); argCtr++) {
+        nsCOMPtr<nsISupports> s;
+        rv = argsArray->QueryElementAt(argCtr, NS_GET_IID(nsISupports),
+                                       getter_AddRefs(s));
+        if (NS_SUCCEEDED(rv))
+            rv = AddSupportsTojsvals(s, argv + argCtr);
+    }
+  else
+    rv = AddSupportsTojsvals(aArgs, argv);
+
+  if (NS_FAILED(rv)) {
+    js_FreeStack(cx, *aMarkp);
+    return rv;
+  }
+  *aArgv = argv;
+  *aArgc = argCount;
+  return NS_OK;
+}
+                                 
+nsresult
+nsJSContext::AddInterfaceTojsvals(nsISupports *aArg, jsval *aArgv)
+{
+  nsresult rv;
+  JSContext *cx = mContext;
+  nsCOMPtr<nsIXPConnect> xpc(do_GetService(nsIXPConnect::GetCID(), &rv));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIXPConnectJSObjectHolder> wrapper;
+  rv = xpc->WrapNative(cx, GetGlobalObject()->GetGlobalJSObject(), aArg,
+              NS_GET_IID(nsISupports), getter_AddRefs(wrapper));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  JSObject *obj;
+  rv = wrapper->GetJSObject(&obj);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  *aArgv = OBJECT_TO_JSVAL(obj);
+  return NS_OK;
+}
+
+
+nsresult
+nsJSContext::AddSupportsTojsvals(nsISupports *aArg, jsval *aArgv)
+{
+  if (!aArg) {
+    *aArgv = JSVAL_NULL;
+    return NS_OK;
+  }
+
+  JSContext *cx = mContext;
+  nsCOMPtr<nsISupportsPrimitive> argPrimitive(do_QueryInterface(aArg));
+  if (!argPrimitive)
+    return AddInterfaceTojsvals(aArg, aArgv);
+
+  PRUint16 type;
+  argPrimitive->GetType(&type);
+
+  switch(type) {
+    case nsISupportsPrimitive::TYPE_CSTRING : {
+      nsCOMPtr<nsISupportsCString> p(do_QueryInterface(argPrimitive));
+      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
+
+      nsCAutoString data;
+
+      p->GetData(data);
+
+      
+      JSString *str = ::JS_NewStringCopyN(cx, data.get(), data.Length());
+      NS_ENSURE_TRUE(str, NS_ERROR_OUT_OF_MEMORY);
+
+      *aArgv = STRING_TO_JSVAL(str);
+
+      break;
+    }
+    case nsISupportsPrimitive::TYPE_STRING : {
+      nsCOMPtr<nsISupportsString> p(do_QueryInterface(argPrimitive));
+      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
+
+      nsAutoString data;
+
+      p->GetData(data);
+
+      // cast is probably safe since wchar_t and jschar are expected
+      // to be equivalent; both unsigned 16-bit entities
+      JSString *str =
+        ::JS_NewUCStringCopyN(cx,
+                              NS_REINTERPRET_CAST(const jschar *,data.get()),
+                              data.Length());
+      NS_ENSURE_TRUE(str, NS_ERROR_OUT_OF_MEMORY);
+
+      *aArgv = STRING_TO_JSVAL(str);
+      break;
+    }
+    case nsISupportsPrimitive::TYPE_PRBOOL : {
+      nsCOMPtr<nsISupportsPRBool> p(do_QueryInterface(argPrimitive));
+      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
+
+      PRBool data;
+
+      p->GetData(&data);
+
+      *aArgv = BOOLEAN_TO_JSVAL(data);
+
+      break;
+    }
+    case nsISupportsPrimitive::TYPE_PRUINT8 : {
+      nsCOMPtr<nsISupportsPRUint8> p(do_QueryInterface(argPrimitive));
+      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
+
+      PRUint8 data;
+
+      p->GetData(&data);
+
+      *aArgv = INT_TO_JSVAL(data);
+
+      break;
+    }
+    case nsISupportsPrimitive::TYPE_PRUINT16 : {
+      nsCOMPtr<nsISupportsPRUint16> p(do_QueryInterface(argPrimitive));
+      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
+
+      PRUint16 data;
+
+      p->GetData(&data);
+
+      *aArgv = INT_TO_JSVAL(data);
+
+      break;
+    }
+    case nsISupportsPrimitive::TYPE_PRUINT32 : {
+      nsCOMPtr<nsISupportsPRUint32> p(do_QueryInterface(argPrimitive));
+      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
+
+      PRUint32 data;
+
+      p->GetData(&data);
+
+      *aArgv = INT_TO_JSVAL(data);
+
+      break;
+    }
+    case nsISupportsPrimitive::TYPE_CHAR : {
+      nsCOMPtr<nsISupportsChar> p(do_QueryInterface(argPrimitive));
+      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
+
+      char data;
+
+      p->GetData(&data);
+
+      JSString *str = ::JS_NewStringCopyN(cx, &data, 1);
+      NS_ENSURE_TRUE(str, NS_ERROR_OUT_OF_MEMORY);
+
+      *aArgv = STRING_TO_JSVAL(str);
+
+      break;
+    }
+    case nsISupportsPrimitive::TYPE_PRINT16 : {
+      nsCOMPtr<nsISupportsPRInt16> p(do_QueryInterface(argPrimitive));
+      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
+
+      PRInt16 data;
+
+      p->GetData(&data);
+
+      *aArgv = INT_TO_JSVAL(data);
+
+      break;
+    }
+    case nsISupportsPrimitive::TYPE_PRINT32 : {
+      nsCOMPtr<nsISupportsPRInt32> p(do_QueryInterface(argPrimitive));
+      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
+
+      PRInt32 data;
+
+      p->GetData(&data);
+
+      *aArgv = INT_TO_JSVAL(data);
+
+      break;
+    }
+    case nsISupportsPrimitive::TYPE_FLOAT : {
+      nsCOMPtr<nsISupportsFloat> p(do_QueryInterface(argPrimitive));
+      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
+
+      float data;
+
+      p->GetData(&data);
+
+      jsdouble *d = ::JS_NewDouble(cx, data);
+
+      *aArgv = DOUBLE_TO_JSVAL(d);
+
+      break;
+    }
+    case nsISupportsPrimitive::TYPE_DOUBLE : {
+      nsCOMPtr<nsISupportsDouble> p(do_QueryInterface(argPrimitive));
+      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
+
+      double data;
+
+      p->GetData(&data);
+
+      jsdouble *d = ::JS_NewDouble(cx, data);
+
+      *aArgv = DOUBLE_TO_JSVAL(d);
+
+      break;
+    }
+    case nsISupportsPrimitive::TYPE_INTERFACE_POINTER : {
+      nsCOMPtr<nsISupportsInterfacePointer> p(do_QueryInterface(argPrimitive));
+      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
+
+      nsCOMPtr<nsISupports> data;
+      nsIID *iid = nsnull;
+
+      p->GetData(getter_AddRefs(data));
+      p->GetDataIID(&iid);
+      NS_ENSURE_TRUE(iid, NS_ERROR_UNEXPECTED);
+
+      AutoFree iidGuard(iid); // Free iid upon destruction.
+
+      nsresult rv;
+      nsCOMPtr<nsIXPConnect> xpc(do_GetService(nsIXPConnect::GetCID(), &rv));
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      nsCOMPtr<nsIXPConnectJSObjectHolder> wrapper;
+      rv = xpc->WrapNative(cx, ::JS_GetGlobalObject(cx), data,
+                           *iid, getter_AddRefs(wrapper));
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      JSObject *obj;
+      rv = wrapper->GetJSObject(&obj);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      *aArgv = OBJECT_TO_JSVAL(obj);
+
+      break;
+    }
+    case nsISupportsPrimitive::TYPE_ID :
+    case nsISupportsPrimitive::TYPE_PRUINT64 :
+    case nsISupportsPrimitive::TYPE_PRINT64 :
+    case nsISupportsPrimitive::TYPE_PRTIME :
+    case nsISupportsPrimitive::TYPE_VOID : {
+      NS_WARNING("Unsupported primitive type used");
+      *aArgv = JSVAL_NULL;
+      break;
+    }
+    default : {
+      NS_WARNING("Unknown primitive type used");
+      *aArgv = JSVAL_NULL;
+      break;
+    }
+  }
+  return NS_OK;
+}
+
 nsresult
 nsJSContext::FindXPCNativeWrapperClass(nsIXPConnectJSObjectHolder *aHolder)
 {
@@ -1972,21 +2432,23 @@ static JSFunctionSpec JProfFunctions[] = {
 #endif /* defined(MOZ_JPROF) */
 
 nsresult
-nsJSContext::InitClasses(JSObject *aGlobalObj)
+nsJSContext::InitClasses(void *aGlobalObj)
 {
   nsresult rv = NS_OK;
 
+  JSObject *globalObj = NS_STATIC_CAST(JSObject *, aGlobalObj);
+
   rv = InitializeExternalClasses();
   NS_ENSURE_SUCCESS(rv, rv);
 
-  rv = InitializeLiveConnectClasses(aGlobalObj);
+  rv = InitializeLiveConnectClasses(globalObj);
   NS_ENSURE_SUCCESS(rv, rv);
 
-  rv = nsDOMClassInfo::InitDOMJSClass(mContext, aGlobalObj);
+  rv = nsDOMClassInfo::InitDOMJSClass(mContext, globalObj);
   NS_ENSURE_SUCCESS(rv, rv);
 
   // Initialize the options object and set default options in mContext
-  JSObject *optionsObj = ::JS_DefineObject(mContext, aGlobalObj, "_options",
+  JSObject *optionsObj = ::JS_DefineObject(mContext, globalObj, "_options",
                                            &OptionsClass, nsnull, 0);
   if (optionsObj &&
       ::JS_DefineProperties(mContext, optionsObj, OptionsProperties)) {
@@ -1997,17 +2459,24 @@ nsJSContext::InitClasses(JSObject *aGlobalObj)
 
 #ifdef NS_TRACE_MALLOC
   // Attempt to initialize TraceMalloc functions
-  ::JS_DefineFunctions(mContext, aGlobalObj, TraceMallocFunctions);
+  ::JS_DefineFunctions(mContext, globalObj, TraceMallocFunctions);
 #endif
 
 #ifdef MOZ_JPROF
   // Attempt to initialize JProf functions
-  ::JS_DefineFunctions(mContext, aGlobalObj, JProfFunctions);
+  ::JS_DefineFunctions(mContext, globalObj, JProfFunctions);
 #endif
 
   return rv;
 }
 
+nsresult
+nsJSContext::FinalizeClasses(void *aGlobalObj)
+{
+  // nothing to do here!
+  return NS_OK;
+}
+
 void
 nsJSContext::WillInitializeContext()
 {
@@ -2101,6 +2570,8 @@ nsJSContext::GetScriptsEnabled()
 void
 nsJSContext::SetScriptsEnabled(PRBool aEnabled, PRBool aFireTimeouts)
 {
+  // eeek - this seems the wrong way around - the global should callback
+  // into each context, so every language is disabled.
   mScriptsEnabled = aEnabled;
 
   nsIScriptGlobalObject *global = GetGlobalObject();
@@ -2207,10 +2678,56 @@ DOMGCCallback(JSContext *cx, JSGCStatus status)
 
   return result;
 }
+/**********************************************************************
+ * nsJSRuntime implementation
+ *********************************************************************/
+
+// QueryInterface implementation for nsJSRuntime
+NS_INTERFACE_MAP_BEGIN(nsJSRuntime)
+  NS_INTERFACE_MAP_ENTRY(nsILanguageRuntime)
+NS_INTERFACE_MAP_END
+
+
+NS_IMPL_ADDREF(nsJSRuntime)
+NS_IMPL_RELEASE(nsJSRuntime)
+
+nsresult
+nsJSRuntime::CreateContext(nsIScriptContext **aContext)
+{
+  nsresult rv = nsJSRuntime::Init();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIScriptContext> scriptContext;
+  
+  *aContext = new nsJSContext(sRuntime);
+  NS_ENSURE_TRUE(*aContext, NS_ERROR_OUT_OF_MEMORY);
+  NS_ADDREF(*aContext);
+  return rv;
+}
+
+nsresult
+nsJSRuntime::ParseVersion(const nsString &aVersionStr, PRUint32 *flags)
+{
+    NS_PRECONDITION(flags, "Null flags param?");
+    PRUint32 jsVersion = JSVERSION_UNKNOWN;
+    if (aVersionStr.Length() != 3 || aVersionStr[0] != '1' || aVersionStr[1] != '.')
+        jsVersion = JSVERSION_UNKNOWN;
+    else switch (aVersionStr[2]) {
+        case '0': jsVersion = JSVERSION_1_0; break;
+        case '1': jsVersion = JSVERSION_1_1; break;
+        case '2': jsVersion = JSVERSION_1_2; break;
+        case '3': jsVersion = JSVERSION_1_3; break;
+        case '4': jsVersion = JSVERSION_1_4; break;
+        case '5': jsVersion = JSVERSION_1_5; break;
+        default:  jsVersion = JSVERSION_UNKNOWN;
+    }
+    *flags = jsVersion;
+    return NS_OK;
+}
 
 //static
 void
-nsJSEnvironment::Startup()
+nsJSRuntime::Startup()
 {
   // initialize all our statics, so that we can restart XPCOM
   sGCTimer = nsnull;
@@ -2254,9 +2771,9 @@ ObjectPrincipalFinder(JSContext *cx, JSObject *obj)
   return jsPrincipals;
 }
 
-// static
+//static
 nsresult
-nsJSEnvironment::Init()
+nsJSRuntime::Init()
 {
   if (sIsInitialized) {
     return NS_OK;
@@ -2284,7 +2801,7 @@ nsJSEnvironment::Init()
 #endif
 
   NS_ASSERTION(!gOldJSGCCallback,
-               "nsJSEnvironment initialized more than once");
+               "nsJSRuntime initialized more than once");
 
   // Save the old GC callback to chain to it, for GC-observing generality.
   gOldJSGCCallback = ::JS_SetGCCallbackRT(sRuntime, DOMGCCallback);
@@ -2337,8 +2854,7 @@ nsJSEnvironment::Init()
   return rv;
 }
 
-// static
-void nsJSEnvironment::ShutDown()
+void nsJSRuntime::ShutDown()
 {
   if (sGCTimer) {
     // We're being shut down, if we have a GC timer scheduled, cancel
@@ -2373,44 +2889,57 @@ void nsJSEnvironment::ShutDown()
   sDidShutdown = PR_TRUE;
 }
 
-// static
-nsresult
-nsJSEnvironment::CreateNewContext(nsIScriptContext **aContext)
+// A factory for the runtime.
+nsresult NS_CreateJSRuntime(nsILanguageRuntime **aRuntime)
 {
-  *aContext = new nsJSContext(sRuntime);
-  NS_ENSURE_TRUE(*aContext, NS_ERROR_OUT_OF_MEMORY);
-
-  NS_ADDREF(*aContext);
-  return NS_OK;
+    *aRuntime = new nsJSRuntime();
+    if (*aRuntime == nsnull)
+        return NS_ERROR_OUT_OF_MEMORY;
+    NS_IF_ADDREF(*aRuntime);
+    return NS_OK;
 }
 
-nsresult
-NS_CreateScriptContext(nsIScriptGlobalObject *aGlobal,
-                       nsIScriptContext **aContext)
+
+/**********************************************************************
+ * nsJSScriptBinding implementation
+ *********************************************************************/
+
+// QueryInterface implementation for nsJSScriptBinding
+NS_INTERFACE_MAP_BEGIN(nsJSScriptBinding)
+  NS_INTERFACE_MAP_ENTRY(nsIScriptBinding)
+NS_INTERFACE_MAP_END
+
+
+NS_IMPL_ADDREF(nsJSScriptBinding)
+NS_IMPL_RELEASE(nsJSScriptBinding)
+
+nsJSScriptBinding::nsJSScriptBinding(nsIXPConnectJSObjectHolder *aHolder)
+{
+    mHolder = aHolder;
+}
+nsJSScriptBinding::~nsJSScriptBinding()
 {
-  nsresult rv = nsJSEnvironment::Init();
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  nsCOMPtr<nsIScriptContext> scriptContext;
-  rv = nsJSEnvironment::CreateNewContext(getter_AddRefs(scriptContext));
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  scriptContext->WillInitializeContext();
-
-  // Bind the script context and the global object
-  rv = scriptContext->InitContext(aGlobal);
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  scriptContext->DidInitializeContext();
-
-  if (aGlobal) {
-    aGlobal->SetContext(scriptContext);
-  }
-
-  *aContext = scriptContext;
-
-  NS_ADDREF(*aContext);
-
-  return rv;
+}
+
+void *
+nsJSScriptBinding::GetNativeObject()
+{
+    JSObject *ret;
+    nsresult rv = mHolder->GetJSObject(&ret);
+    NS_ASSERTION(!NS_FAILED(rv), "Object has no JSObject?");
+    return ret;
+}
+
+nsISupports *
+nsJSScriptBinding::GetTarget()
+{
+    // Since we are specified only as a aw nsISupports pointer, it's
+    // important that it point to the same object that the WrappedNative wraps.
+    // (In the case of a tearoff, the tearoff will not persist).
+    // XXXMarkh - is this correct?
+
+    nsCOMPtr<nsIXPConnectWrappedNative> wrapper = do_QueryInterface(mHolder);
+    NS_ASSERTION(wrapper, "wrapper must impl nsIXPConnectWrappedNative");
+    return wrapper == nsnull ? nsnull : wrapper->Native();
 }
 
diff --git a/mozilla/dom/src/base/nsJSEnvironment.h b/mozilla/dom/src/base/nsJSEnvironment.h
index bbe5c54c711..2df1a325042 100644
--- a/mozilla/dom/src/base/nsJSEnvironment.h
+++ b/mozilla/dom/src/base/nsJSEnvironment.h
@@ -38,9 +38,9 @@
 #define nsJSEnvironment_h___
 
 #include "nsIScriptContext.h"
+#include "nsILanguageRuntime.h"
 #include "nsCOMPtr.h"
 #include "jsapi.h"
-#include "nsCOMPtr.h"
 #include "nsIObserver.h"
 #include "nsIScriptSecurityManager.h"
 #include "nsIXPCScriptNotify.h"
@@ -58,12 +58,14 @@ public:
 
   NS_DECL_ISUPPORTS
 
+  virtual PRUint32 GetLanguage() { return nsIProgrammingLanguage::JAVASCRIPT; }
+
   virtual nsresult EvaluateString(const nsAString& aScript,
                                   void *aScopeObject,
                                   nsIPrincipal *principal,
                                   const char *aURL,
                                   PRUint32 aLineNo,
-                                  const char* aVersion,
+                                  PRUint32 aVersion,
                                   nsAString *aRetValue,
                                   PRBool* aIsUndefined);
   virtual nsresult EvaluateStringWithValue(const nsAString& aScript,
@@ -71,7 +73,7 @@ public:
                                      nsIPrincipal *aPrincipal,
                                      const char *aURL,
                                      PRUint32 aLineNo,
-                                     const char* aVersion,
+                                     PRUint32 aVersion,
                                      void* aRetValue,
                                      PRBool* aIsUndefined);
 
@@ -81,13 +83,21 @@ public:
                                  nsIPrincipal *principal,
                                  const char *aURL,
                                  PRUint32 aLineNo,
-                                 const char* aVersion,
+                                 PRUint32 aVersion,
                                  void** aScriptObject);
   virtual nsresult ExecuteScript(void* aScriptObject,
                                  void *aScopeObject,
                                  nsAString* aRetValue,
                                  PRBool* aIsUndefined);
-  virtual nsresult CompileEventHandler(void *aTarget,
+
+  virtual nsresult GetScriptBinding(nsISupports *aObject, void *aScope,
+                                    nsIScriptBinding **aBinding);
+
+  virtual nsresult GetScriptBindingHandler(nsIScriptBinding *aBinding,
+                                           nsString &name,
+                                           void **handler);
+
+  virtual nsresult CompileEventHandler(nsIScriptBinding *aTarget,
                                        nsIAtom *aName,
                                        const char *aEventName,
                                        const nsAString& aBody,
@@ -95,9 +105,9 @@ public:
                                        PRUint32 aLineNo,
                                        PRBool aShared,
                                        void** aHandler);
-  virtual nsresult CallEventHandler(JSObject *aTarget, JSObject *aHandler, 
-                                    uintN argc, jsval *argv, jsval* rval);
-  virtual nsresult BindCompiledEventHandler(void *aTarget,
+  virtual nsresult CallEventHandler(nsIScriptBinding* aTarget, void* aHandler,
+                                    nsIArray *argv, nsISupports **rv);
+  virtual nsresult BindCompiledEventHandler(nsIScriptBinding *aTarget,
                                             nsIAtom *aName,
                                             void *aHandler);
   virtual nsresult CompileFunction(void* aTarget,
@@ -110,11 +120,16 @@ public:
                                    PRBool aShared,
                                    void** aFunctionObject);
 
-  virtual void SetDefaultLanguageVersion(const char* aVersion);
+  virtual nsresult AddGCRoot(void *object, const char *desc);
+  virtual nsresult RemoveGCRoot(void *object);
+
+  virtual void SetDefaultLanguageVersion(PRUint32 aVersion);
   virtual nsIScriptGlobalObject *GetGlobalObject();
   virtual void *GetNativeContext();
+  virtual void *GetNativeGlobal();
   virtual nsresult InitContext(nsIScriptGlobalObject *aGlobalObject);
   virtual PRBool IsContextInitialized();
+
   virtual void GC();
 
   virtual void ScriptEvaluated(PRBool aTerminated);
@@ -125,16 +140,23 @@ public:
   virtual PRBool GetScriptsEnabled();
   virtual void SetScriptsEnabled(PRBool aEnabled, PRBool aFireTimeouts);
 
+  virtual nsresult SetProperty(void *aTarget, const char *aPropName, nsISupports *aVal);
+
   virtual PRBool GetProcessingScriptTag();
   virtual void SetProcessingScriptTag(PRBool aResult);
 
   virtual void SetGCOnDestruction(PRBool aGCOnDestruction);
 
-  virtual nsresult InitClasses(JSObject *aGlobalObj);
+  virtual nsresult InitClasses(void *aGlobalObj);
+  virtual nsresult FinalizeClasses(void* aGlobalObj);
 
   virtual void WillInitializeContext();
   virtual void DidInitializeContext();
 
+  nsresult ConvertSupportsTojsvals(nsISupports *aArgs,
+                                   PRUint32 *aArgc, jsval **aArgv,
+                                   void **aMarkp);
+
   NS_DECL_NSIXPCSCRIPTNOTIFY
 
   NS_DECL_NSITIMERCALLBACK
@@ -147,6 +169,9 @@ protected:
 
   void FireGCTimer();
 
+  nsresult   AddSupportsTojsvals(nsISupports *aArg, jsval *aArgv);
+  nsresult   AddInterfaceTojsvals(nsISupports *aArg, jsval *aArgv);
+
 private:
   JSContext *mContext;
   PRUint32 mNumEvaluations;
@@ -232,25 +257,51 @@ private:
 
 class nsIJSRuntimeService;
 
-class nsJSEnvironment
+class nsJSRuntime : public nsILanguageRuntime
 {
 private:
   static JSRuntime *sRuntime;
 
 public:
+  // nsISupports
+  NS_DECL_ISUPPORTS
+
+  // nsILanguageRuntime
+  virtual void ShutDown();
+
+  virtual PRUint32 GetLanguage() {
+            return nsIProgrammingLanguage::JAVASCRIPT;
+  }
+
+  virtual nsresult CreateContext(nsIScriptContext **ret);
+
+  virtual nsresult ParseVersion(const nsString &aVersionStr, PRUint32 *flags);
+  
+  // Private stuff.
   // called from the module Ctor to initialize statics
   static void Startup();
 
   static nsresult Init();
+};
 
-  static nsresult CreateNewContext(nsIScriptContext **aContext);
 
-  static void ShutDown();
+class nsJSScriptBinding : public nsIScriptBinding {
+public:
+  nsJSScriptBinding(nsIXPConnectJSObjectHolder *aHolder);
+  virtual ~nsJSScriptBinding();
+
+  NS_DECL_ISUPPORTS
+
+
+  virtual PRUint32 GetLanguage() {return nsIProgrammingLanguage::JAVASCRIPT;}
+  void *GetNativeObject();
+  nsISupports *GetTarget();
+protected:
+  nsCOMPtr<nsIXPConnectJSObjectHolder> mHolder;
 };
 
 /* factory function */
-nsresult NS_CreateScriptContext(nsIScriptGlobalObject *aGlobal,
-                                nsIScriptContext **aContext);
+nsresult NS_CreateJSRuntime(nsILanguageRuntime **aRuntime);
 
 /* prototypes */
 void JS_DLL_CALLBACK NS_ScriptErrorReporter(JSContext *cx, const char *message, JSErrorReport *report);
diff --git a/mozilla/dom/src/base/nsJSUtils.cpp b/mozilla/dom/src/base/nsJSUtils.cpp
index 37399728e44..6c232bbb01f 100644
--- a/mozilla/dom/src/base/nsJSUtils.cpp
+++ b/mozilla/dom/src/base/nsJSUtils.cpp
@@ -55,6 +55,7 @@
 #include "nsCOMPtr.h"
 #include "nsContentUtils.h"
 
+#include "nsDOMJSUtils.h" // for GetScriptContextFromJSContext
 
 JSBool
 nsJSUtils::GetCallingLocation(JSContext* aContext, const char* *aFilename,
diff --git a/mozilla/dom/src/events/nsJSEventListener.cpp b/mozilla/dom/src/events/nsJSEventListener.cpp
index 0da4399686f..5d633d085a1 100644
--- a/mozilla/dom/src/events/nsJSEventListener.cpp
+++ b/mozilla/dom/src/events/nsJSEventListener.cpp
@@ -39,22 +39,23 @@
 #include "nsString.h"
 #include "nsReadableUtils.h"
 #include "nsIServiceManager.h"
-#include "nsIJSContextStack.h"
 #include "nsIScriptSecurityManager.h"
 #include "nsIScriptContext.h"
+#include "nsIScriptGlobalObject.h"
 #include "nsIXPConnect.h"
 #include "nsIPrivateDOMEvent.h"
 #include "nsGUIEvent.h"
 #include "nsContentUtils.h"
+#include "nsArray.h"
 
 
 /*
  * nsJSEventListener implementation
  */
 nsJSEventListener::nsJSEventListener(nsIScriptContext *aContext,
-                                     JSObject *aScopeObject,
-                                     nsISupports *aObject)
-  : nsIJSEventListener(aContext, aScopeObject, aObject),
+                                     nsIScriptGlobalObject *aScopeObject,
+                                     nsIScriptBinding *aBinding)
+  : nsIJSEventListener(aContext, aScopeObject, aBinding),
     mReturnResult(nsReturnResult_eNotSet)
 {
 }
@@ -84,7 +85,8 @@ nsJSEventListener::SetEventName(nsIAtom* aName)
 nsresult
 nsJSEventListener::HandleEvent(nsIDOMEvent* aEvent)
 {
-  jsval funval;
+  nsresult rv;
+  nsCOMPtr<nsIArray> iargv;
   jsval arg;
   jsval *argv = &arg;
   PRInt32 argc = 0;
@@ -115,29 +117,11 @@ nsJSEventListener::HandleEvent(nsIDOMEvent* aEvent)
     mEventName->ToString(eventString);
   }
 
-  nsresult rv;
-  nsIXPConnect *xpc = nsContentUtils::XPConnect();
-
-  // root
-  nsCOMPtr<nsIXPConnectJSObjectHolder> wrapper;
-  rv = xpc->WrapNative(cx, mScopeObject, mTarget, NS_GET_IID(nsISupports),
-                       getter_AddRefs(wrapper));
+  void *funcval;
+  rv = mContext->GetScriptBindingHandler(mBinding, eventString, &funcval);
   NS_ENSURE_SUCCESS(rv, rv);
-
-  JSObject* obj = nsnull;
-  rv = wrapper->GetJSObject(&obj);
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  if (!JS_LookupUCProperty(cx, obj,
-                           NS_REINTERPRET_CAST(const jschar *,
-                                               eventString.get()),
-                           eventString.Length(), &funval)) {
-    return NS_ERROR_FAILURE;
-  }
-
-  if (JS_TypeOfValue(cx, funval) != JSTYPE_FUNCTION) {
+  if (!funcval)
     return NS_OK;
-  }
 
   PRBool handledScriptError = PR_FALSE;
   if (eventString.EqualsLiteral("onerror")) {
@@ -155,25 +139,24 @@ nsJSEventListener::HandleEvent(nsIDOMEvent* aEvent)
       NS_ENSURE_TRUE(argv, NS_ERROR_OUT_OF_MEMORY);
       argc = 3;
       handledScriptError = PR_TRUE;
+      NS_ERROR("nsJSEventListener ignoring args!");
     }
   }
 
   if (!handledScriptError) {
-    rv = xpc->WrapNative(cx, obj, aEvent, NS_GET_IID(nsIDOMEvent),
-                         getter_AddRefs(wrapper));
+    nsCOMPtr<nsIMutableArray> tempargv;
+    rv = NS_NewArray(getter_AddRefs(tempargv));
     NS_ENSURE_SUCCESS(rv, rv);
-
-    JSObject *eventObj = nsnull;
-    rv = wrapper->GetJSObject(&eventObj);
+    NS_ENSURE_TRUE(tempargv != nsnull, NS_ERROR_OUT_OF_MEMORY);
+    rv = tempargv->AppendElement(aEvent, PR_FALSE);
     NS_ENSURE_SUCCESS(rv, rv);
-
-    argv[0] = OBJECT_TO_JSVAL(eventObj);
-    argc = 1;
+    iargv = do_QueryInterface(tempargv);
   }
 
-  jsval rval;
-  rv = mContext->CallEventHandler(obj, JSVAL_TO_OBJECT(funval), argc, argv,
-                                  &rval);
+  nsCOMPtr<nsISupports> irv;
+  // XXX - fix return val!
+  jsval rval = JSVAL_VOID;
+  rv = mContext->CallEventHandler(mBinding, funcval, iargv, getter_AddRefs(irv));
 
   if (argv != &arg) {
     ::JS_PopArguments(cx, stackPtr);
@@ -222,11 +205,11 @@ nsJSEventListener::HandleEvent(nsIDOMEvent* aEvent)
  */
 
 nsresult
-NS_NewJSEventListener(nsIScriptContext *aContext, JSObject *aScopeObject,
-                      nsISupports *aObject, nsIDOMEventListener ** aReturn)
+NS_NewJSEventListener(nsIScriptContext *aContext, nsIScriptGlobalObject *aScopeGlobal,
+                      nsIScriptBinding *aBinding, nsIDOMEventListener ** aReturn)
 {
   nsJSEventListener* it =
-    new nsJSEventListener(aContext, aScopeObject, aObject);
+    new nsJSEventListener(aContext, aScopeGlobal, aBinding);
   if (!it) {
     return NS_ERROR_OUT_OF_MEMORY;
   }
diff --git a/mozilla/dom/src/events/nsJSEventListener.h b/mozilla/dom/src/events/nsJSEventListener.h
index 526e5f4a0bc..19e938581bf 100644
--- a/mozilla/dom/src/events/nsJSEventListener.h
+++ b/mozilla/dom/src/events/nsJSEventListener.h
@@ -47,12 +47,13 @@
 #include "nsIScriptContext.h"
 
 //nsIDOMMouseListener interface
+// misnamed - JS grip is broken!
 class nsJSEventListener : public nsIDOMEventListener,
                           public nsIJSEventListener
 {
 public:
-  nsJSEventListener(nsIScriptContext *aContext, JSObject *aScopeObject,
-                    nsISupports* aObject);
+  nsJSEventListener(nsIScriptContext *aContext, nsIScriptGlobalObject *aScopeObject,
+                    nsIScriptBinding* aObject);
   virtual ~nsJSEventListener();
 
   NS_DECL_ISUPPORTS
diff --git a/mozilla/dom/src/jsurl/nsJSProtocolHandler.cpp b/mozilla/dom/src/jsurl/nsJSProtocolHandler.cpp
index 19eb3b9e9fb..ed2f09372a6 100644
--- a/mozilla/dom/src/jsurl/nsJSProtocolHandler.cpp
+++ b/mozilla/dom/src/jsurl/nsJSProtocolHandler.cpp
@@ -65,7 +65,6 @@
 #include "nsXPIDLString.h"
 #include "prprf.h"
 #include "nsEscape.h"
-#include "nsIJSContextStack.h"
 #include "nsIWebNavigation.h"
 #include "nsIDocShell.h"
 #include "nsIContentViewer.h"
@@ -260,7 +259,7 @@ nsresult nsJSThunk::EvaluateScript(nsIChannel *aChannel)
     PRBool bIsUndefined;
 
     rv = scriptContext->EvaluateString(NS_ConvertUTF8toUCS2(script),
-                                       globalJSObject, // obj
+                                       global, // obj
                                        principal,
                                        url.get(),      // url
                                        1,              // line no
diff --git a/mozilla/embedding/components/windowwatcher/public/nsPIWindowWatcher.idl b/mozilla/embedding/components/windowwatcher/public/nsPIWindowWatcher.idl
index e6ad82f2d19..a4f3cc80bec 100644
--- a/mozilla/embedding/components/windowwatcher/public/nsPIWindowWatcher.idl
+++ b/mozilla/embedding/components/windowwatcher/public/nsPIWindowWatcher.idl
@@ -46,6 +46,7 @@ interface nsIDOMWindow;
 interface nsISimpleEnumerator;
 interface nsIWebBrowserChrome;
 interface nsIDocShellTreeItem;
+interface nsIArray;
 
 %{C++
 #include "jspubtd.h"
@@ -80,14 +81,12 @@ interface nsPIWindowWatcher : nsISupports
       @param aName window name from JS window.open. can be null.
       @param aFeatures window features from JS window.open. can be null.
       @param aDialog use dialog defaults (see nsIDOMWindowInternal::openDialog)
-      @param argc count of argv arguments
-      @param argv extra JS arguments, if any
-                  (see nsIDOMWindowInternal::openDialog)
+      @param aArgs Window argument
       @return the new window
   */
   nsIDOMWindow openWindowJS(in nsIDOMWindow aParent, in string aUrl,
                in string aName, in string aFeatures, in boolean aDialog,
-               in PRUint32 argc, in jsvalptr argv);
+               in nsIArray aArgs);
 
   /**
    * Find a named docshell tree item amongst all windows registered
diff --git a/mozilla/embedding/components/windowwatcher/src/nsWWJSUtils.cpp b/mozilla/embedding/components/windowwatcher/src/nsWWJSUtils.cpp
index f01b368c938..63083608986 100644
--- a/mozilla/embedding/components/windowwatcher/src/nsWWJSUtils.cpp
+++ b/mozilla/embedding/components/windowwatcher/src/nsWWJSUtils.cpp
@@ -44,6 +44,7 @@
 #include "nsIScriptGlobalObject.h"
 #include "nsWWJSUtils.h"
 #include "nsIXPConnect.h"
+#include "nsDOMJSUtils.h"
 
 nsIScriptGlobalObject *
 nsWWJSUtils::GetStaticScriptGlobal(JSContext* aContext, JSObject* aObj)
diff --git a/mozilla/embedding/components/windowwatcher/src/nsWindowWatcher.cpp b/mozilla/embedding/components/windowwatcher/src/nsWindowWatcher.cpp
index bf944bafc9f..dfa202487c4 100644
--- a/mozilla/embedding/components/windowwatcher/src/nsWindowWatcher.cpp
+++ b/mozilla/embedding/components/windowwatcher/src/nsWindowWatcher.cpp
@@ -67,9 +67,7 @@
 #include "nsIObserverService.h"
 #include "nsIScriptGlobalObject.h"
 #include "nsIScriptSecurityManager.h"
-#include "nsISupportsArray.h"
 #include "nsXPCOM.h"
-#include "nsISupportsPrimitives.h"
 #include "nsIURI.h"
 #include "nsIWebBrowser.h"
 #include "nsIWebBrowserChrome.h"
@@ -81,6 +79,7 @@
 #include "nsIMarkupDocumentViewer.h"
 #include "nsIContentViewer.h"
 #include "nsIDocumentViewer.h"
+#include "nsArray.h"
 
 #include "nsIPrefBranch.h"
 #include "nsIPrefService.h"
@@ -399,25 +398,6 @@ nsresult JSContextAutoPopper::Push(JSContext *cx)
   return mContext ? NS_OK : NS_ERROR_FAILURE; 
 }
 
-/****************************************************************
- ************************** AutoFree ****************************
- ****************************************************************/
-
-class AutoFree {
-public:
-  AutoFree(void *aPtr) : mPtr(aPtr) {
-  }
-  ~AutoFree() {
-    if (mPtr)
-      nsMemory::Free(mPtr);
-  }
-  void Invalidate() {
-    mPtr = 0;
-  }
-private:
-  void *mPtr;
-};
-
 /****************************************************************
  *********************** nsWindowWatcher ************************
  ****************************************************************/
@@ -461,24 +441,25 @@ nsWindowWatcher::OpenWindow(nsIDOMWindow *aParent,
                             nsISupports *aArguments,
                             nsIDOMWindow **_retval)
 {
-  PRUint32  argc;
-  jsval    *argv = nsnull;
-  JSContext *cx;
-  void *mark;
-  nsresult  rv;
-
-  rv = ConvertSupportsTojsvals(aParent, aArguments, &argc, &argv, &cx, &mark);
-  if (NS_SUCCEEDED(rv)) {
-    PRBool dialog = argc == 0 ? PR_FALSE : PR_TRUE;
-    rv = OpenWindowJS(aParent, aUrl, aName, aFeatures, dialog, argc, argv,
-                      _retval);
-
-    if (argv) {
-      js_FreeStack(cx, mark);
+  nsCOMPtr<nsIArray> argsArray;
+  PRUint32 argc = 0;
+  if (aArguments) {
+    // If aArguments is not already an array, make it one.
+    argsArray = do_QueryInterface(aArguments);
+    if (argsArray == nsnull) {
+        nsCOMPtr<nsIMutableArray> tempArray;
+        nsresult rv = NS_NewArray(getter_AddRefs(tempArray));
+        NS_ENSURE_SUCCESS(rv, rv);
+        tempArray->AppendElement(aArguments, PR_FALSE);
+        argsArray = do_QueryInterface(tempArray);
+        NS_ENSURE_TRUE(argsArray != nsnull, NS_ERROR_UNEXPECTED);
     }
+    argsArray->GetLength(&argc);
   }
 
-  return rv;
+  PRBool dialog = argc == 0 ? PR_FALSE : PR_TRUE;
+  return OpenWindowJS(aParent, aUrl, aName, aFeatures, dialog, argsArray,
+                      _retval);
 }
 
 NS_IMETHODIMP
@@ -487,8 +468,7 @@ nsWindowWatcher::OpenWindowJS(nsIDOMWindow *aParent,
                               const char *aName,
                               const char *aFeatures,
                               PRBool aDialog,
-                              PRUint32 argc,
-                              jsval *argv,
+                              nsIArray *argv,
                               nsIDOMWindow **_retval)
 {
   nsresult                        rv = NS_OK;
@@ -706,12 +686,12 @@ nsWindowWatcher::OpenWindowJS(nsIDOMWindow *aParent,
     }
   }
 
-  if (aDialog && argc > 0) {
-    rv = AttachArguments(*_retval, argc, argv);
-
-    if (NS_FAILED(rv)) {
-      return rv;
-    }
+  if (aDialog && argv > 0) {
+    // Set the args on the new object.
+    nsCOMPtr<nsIScriptGlobalObject> scriptGlobal(do_QueryInterface(*_retval));
+    NS_ENSURE_TRUE(scriptGlobal, NS_ERROR_UNEXPECTED);
+    rv = scriptGlobal->SetNewArguments(argv);
+    NS_ENSURE_SUCCESS(rv, rv);
   }
 
   /* allow an extant window to keep its name (important for cases like
@@ -1735,337 +1715,6 @@ nsWindowWatcher::SizeOpenedDocShellItem(nsIDocShellTreeItem *aDocShellItem,
   treeOwnerAsWin->SetVisibility(PR_TRUE);
 }
 
-// attach the given array of JS values to the given window, as a property array
-// named "arguments"
-nsresult
-nsWindowWatcher::AttachArguments(nsIDOMWindow *aWindow,
-                                 PRUint32 argc, jsval *argv)
-{
-  if (argc == 0)
-    return NS_OK;
-
-  // copy the extra parameters into a JS Array and attach it
-  nsCOMPtr<nsIScriptGlobalObject> scriptGlobal(do_QueryInterface(aWindow));
-  NS_ENSURE_TRUE(scriptGlobal, NS_ERROR_UNEXPECTED);
-
-  nsIScriptContext *scriptContext = scriptGlobal->GetContext();
-  nsresult rv = NS_OK;
-
-  if (scriptContext) {
-    JSContext *cx;
-    cx = (JSContext *)scriptContext->GetNativeContext();
-
-    JSObject *args;
-    args = ::JS_NewArrayObject(cx, argc, argv);
-    if (args) {
-      rv = scriptGlobal->SetNewArguments(args);
-    }
-  }
-
-  return rv;
-}
-
-nsresult
-nsWindowWatcher::ConvertSupportsTojsvals(nsIDOMWindow *aWindow,
-                                         nsISupports *aArgs,
-                                         PRUint32 *aArgc, jsval **aArgv,
-                                         JSContext **aUsedContext,
-                                         void **aMarkp)
-{
-  nsresult rv = NS_OK;
-
-  *aArgv = nsnull;
-  *aArgc = 0;
-
-  // copy the elements in aArgsArray into the JS array
-  // window.arguments in the new window
-
-  if (!aArgs)
-    return NS_OK;
-
-  PRUint32 argCtr, argCount;
-  nsCOMPtr<nsISupportsArray> argsArray(do_QueryInterface(aArgs));
-
-  if (argsArray) {
-    argsArray->Count(&argCount);
-    if (argCount == 0)
-      return NS_OK;
-  } else
-    argCount = 1; // the nsISupports which is not an array
-
-  JSContext           *cx;
-  JSContextAutoPopper  contextGuard;
-
-  cx = GetJSContextFromWindow(aWindow);
-  if (!cx)
-    cx = GetJSContextFromCallStack();
-  if (!cx) {
-    rv = contextGuard.Push();
-    if (NS_FAILED(rv))
-      return rv;
-    cx = contextGuard.get();
-  }
-
-  jsval *argv = js_AllocStack(cx, argCount, aMarkp);
-  NS_ENSURE_TRUE(argv, NS_ERROR_OUT_OF_MEMORY);
-
-  if (argsArray)
-    for (argCtr = 0; argCtr < argCount && NS_SUCCEEDED(rv); argCtr++) {
-      nsCOMPtr<nsISupports> s(dont_AddRef(argsArray->ElementAt(argCtr)));
-      rv = AddSupportsTojsvals(s, cx, argv + argCtr);
-    }
-  else
-    rv = AddSupportsTojsvals(aArgs, cx, argv);
-
-  if (NS_FAILED(rv)) {
-    js_FreeStack(cx, *aMarkp);
-
-    return rv;
-  }
-
-  *aUsedContext = cx;
-  *aArgv = argv;
-  *aArgc = argCount;
-  return NS_OK;
-}
-
-nsresult
-nsWindowWatcher::AddInterfaceTojsvals(nsISupports *aArg,
-                                      JSContext *cx,
-                                      jsval *aArgv)
-{
-  nsresult rv;
-  nsCOMPtr<nsIXPConnect> xpc(do_GetService(nsIXPConnect::GetCID(), &rv));
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  nsCOMPtr<nsIXPConnectJSObjectHolder> wrapper;
-  rv = xpc->WrapNative(cx, ::JS_GetGlobalObject(cx), aArg,
-              NS_GET_IID(nsISupports), getter_AddRefs(wrapper));
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  JSObject *obj;
-  rv = wrapper->GetJSObject(&obj);
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  *aArgv = OBJECT_TO_JSVAL(obj);
-  return NS_OK;
-}
-
-nsresult
-nsWindowWatcher::AddSupportsTojsvals(nsISupports *aArg,
-                                     JSContext *cx, jsval *aArgv)
-{
-  if (!aArg) {
-    *aArgv = JSVAL_NULL;
-    return NS_OK;
-  }
-
-  nsCOMPtr<nsISupportsPrimitive> argPrimitive(do_QueryInterface(aArg));
-  if (!argPrimitive)
-    return AddInterfaceTojsvals(aArg, cx, aArgv);
-
-  PRUint16 type;
-  argPrimitive->GetType(&type);
-
-  switch(type) {
-    case nsISupportsPrimitive::TYPE_CSTRING : {
-      nsCOMPtr<nsISupportsCString> p(do_QueryInterface(argPrimitive));
-      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
-
-      nsCAutoString data;
-
-      p->GetData(data);
-
-      
-      JSString *str = ::JS_NewStringCopyN(cx, data.get(), data.Length());
-      NS_ENSURE_TRUE(str, NS_ERROR_OUT_OF_MEMORY);
-
-      *aArgv = STRING_TO_JSVAL(str);
-
-      break;
-    }
-    case nsISupportsPrimitive::TYPE_STRING : {
-      nsCOMPtr<nsISupportsString> p(do_QueryInterface(argPrimitive));
-      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
-
-      nsAutoString data;
-
-      p->GetData(data);
-
-      // cast is probably safe since wchar_t and jschar are expected
-      // to be equivalent; both unsigned 16-bit entities
-      JSString *str =
-        ::JS_NewUCStringCopyN(cx,
-                              NS_REINTERPRET_CAST(const jschar *,data.get()),
-                              data.Length());
-      NS_ENSURE_TRUE(str, NS_ERROR_OUT_OF_MEMORY);
-
-      *aArgv = STRING_TO_JSVAL(str);
-      break;
-    }
-    case nsISupportsPrimitive::TYPE_PRBOOL : {
-      nsCOMPtr<nsISupportsPRBool> p(do_QueryInterface(argPrimitive));
-      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
-
-      PRBool data;
-
-      p->GetData(&data);
-
-      *aArgv = BOOLEAN_TO_JSVAL(data);
-
-      break;
-    }
-    case nsISupportsPrimitive::TYPE_PRUINT8 : {
-      nsCOMPtr<nsISupportsPRUint8> p(do_QueryInterface(argPrimitive));
-      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
-
-      PRUint8 data;
-
-      p->GetData(&data);
-
-      *aArgv = INT_TO_JSVAL(data);
-
-      break;
-    }
-    case nsISupportsPrimitive::TYPE_PRUINT16 : {
-      nsCOMPtr<nsISupportsPRUint16> p(do_QueryInterface(argPrimitive));
-      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
-
-      PRUint16 data;
-
-      p->GetData(&data);
-
-      *aArgv = INT_TO_JSVAL(data);
-
-      break;
-    }
-    case nsISupportsPrimitive::TYPE_PRUINT32 : {
-      nsCOMPtr<nsISupportsPRUint32> p(do_QueryInterface(argPrimitive));
-      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
-
-      PRUint32 data;
-
-      p->GetData(&data);
-
-      *aArgv = INT_TO_JSVAL(data);
-
-      break;
-    }
-    case nsISupportsPrimitive::TYPE_CHAR : {
-      nsCOMPtr<nsISupportsChar> p(do_QueryInterface(argPrimitive));
-      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
-
-      char data;
-
-      p->GetData(&data);
-
-      JSString *str = ::JS_NewStringCopyN(cx, &data, 1);
-      NS_ENSURE_TRUE(str, NS_ERROR_OUT_OF_MEMORY);
-
-      *aArgv = STRING_TO_JSVAL(str);
-
-      break;
-    }
-    case nsISupportsPrimitive::TYPE_PRINT16 : {
-      nsCOMPtr<nsISupportsPRInt16> p(do_QueryInterface(argPrimitive));
-      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
-
-      PRInt16 data;
-
-      p->GetData(&data);
-
-      *aArgv = INT_TO_JSVAL(data);
-
-      break;
-    }
-    case nsISupportsPrimitive::TYPE_PRINT32 : {
-      nsCOMPtr<nsISupportsPRInt32> p(do_QueryInterface(argPrimitive));
-      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
-
-      PRInt32 data;
-
-      p->GetData(&data);
-
-      *aArgv = INT_TO_JSVAL(data);
-
-      break;
-    }
-    case nsISupportsPrimitive::TYPE_FLOAT : {
-      nsCOMPtr<nsISupportsFloat> p(do_QueryInterface(argPrimitive));
-      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
-
-      float data;
-
-      p->GetData(&data);
-
-      jsdouble *d = ::JS_NewDouble(cx, data);
-
-      *aArgv = DOUBLE_TO_JSVAL(d);
-
-      break;
-    }
-    case nsISupportsPrimitive::TYPE_DOUBLE : {
-      nsCOMPtr<nsISupportsDouble> p(do_QueryInterface(argPrimitive));
-      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
-
-      double data;
-
-      p->GetData(&data);
-
-      jsdouble *d = ::JS_NewDouble(cx, data);
-
-      *aArgv = DOUBLE_TO_JSVAL(d);
-
-      break;
-    }
-    case nsISupportsPrimitive::TYPE_INTERFACE_POINTER : {
-      nsCOMPtr<nsISupportsInterfacePointer> p(do_QueryInterface(argPrimitive));
-      NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
-
-      nsCOMPtr<nsISupports> data;
-      nsIID *iid = nsnull;
-
-      p->GetData(getter_AddRefs(data));
-      p->GetDataIID(&iid);
-      NS_ENSURE_TRUE(iid, NS_ERROR_UNEXPECTED);
-
-      AutoFree iidGuard(iid); // Free iid upon destruction.
-
-      nsresult rv;
-      nsCOMPtr<nsIXPConnect> xpc(do_GetService(nsIXPConnect::GetCID(), &rv));
-      NS_ENSURE_SUCCESS(rv, rv);
-
-      nsCOMPtr<nsIXPConnectJSObjectHolder> wrapper;
-      rv = xpc->WrapNative(cx, ::JS_GetGlobalObject(cx), data,
-                           *iid, getter_AddRefs(wrapper));
-      NS_ENSURE_SUCCESS(rv, rv);
-
-      JSObject *obj;
-      rv = wrapper->GetJSObject(&obj);
-      NS_ENSURE_SUCCESS(rv, rv);
-
-      *aArgv = OBJECT_TO_JSVAL(obj);
-
-      break;
-    }
-    case nsISupportsPrimitive::TYPE_ID :
-    case nsISupportsPrimitive::TYPE_PRUINT64 :
-    case nsISupportsPrimitive::TYPE_PRINT64 :
-    case nsISupportsPrimitive::TYPE_PRTIME :
-    case nsISupportsPrimitive::TYPE_VOID : {
-      NS_WARNING("Unsupported primitive type used");
-      *aArgv = JSVAL_NULL;
-      break;
-    }
-    default : {
-      NS_WARNING("Unknown primitive type used");
-      *aArgv = JSVAL_NULL;
-      break;
-    }
-  }
-  return NS_OK;
-}
-
 void
 nsWindowWatcher::GetWindowTreeItem(nsIDOMWindow *inWindow,
                                    nsIDocShellTreeItem **outTreeItem)
diff --git a/mozilla/embedding/components/windowwatcher/src/nsWindowWatcher.h b/mozilla/embedding/components/windowwatcher/src/nsWindowWatcher.h
index bef0491c414..66ef4a7079a 100644
--- a/mozilla/embedding/components/windowwatcher/src/nsWindowWatcher.h
+++ b/mozilla/embedding/components/windowwatcher/src/nsWindowWatcher.h
@@ -104,17 +104,6 @@ private:
                                            nsIDOMWindow *aParent,
                                            const char *aFeatures,
                                            PRUint32 aChromeFlags);
-  static nsresult   AttachArguments(nsIDOMWindow *aWindow,
-                                    PRUint32 argc, jsval *argv);
-  static nsresult   ConvertSupportsTojsvals(nsIDOMWindow *aWindow,
-                                            nsISupports *aArgs,
-                                            PRUint32 *aArgc, jsval **aArgv,
-                                            JSContext **aUsedContext,
-                                            void **aMarkp);
-  static nsresult   AddSupportsTojsvals(nsISupports *aArg,
-                                        JSContext *cx, jsval *aArgv);
-  static nsresult   AddInterfaceTojsvals(nsISupports *aArg,
-                                      JSContext *cx, jsval *aArgv);
   static void       GetWindowTreeItem(nsIDOMWindow *inWindow,
                                       nsIDocShellTreeItem **outTreeItem);
   static void       GetWindowTreeOwner(nsIDOMWindow *inWindow,
diff --git a/mozilla/extensions/xmlextras/base/src/nsDOMParser.cpp b/mozilla/extensions/xmlextras/base/src/nsDOMParser.cpp
index f61a94eac5d..387fdab9535 100644
--- a/mozilla/extensions/xmlextras/base/src/nsDOMParser.cpp
+++ b/mozilla/extensions/xmlextras/base/src/nsDOMParser.cpp
@@ -65,6 +65,7 @@
 #include "nsLoadListenerProxy.h"
 #include "nsStreamUtils.h"
 #include "nsNetCID.h"
+#include "nsDOMJSUtils.h" // for GetScriptContextFromJSContext
 
 static NS_DEFINE_IID(kEventQueueServiceCID, NS_EVENTQUEUESERVICE_CID);
 
diff --git a/mozilla/extensions/xmlextras/base/src/nsXMLHttpRequest.cpp b/mozilla/extensions/xmlextras/base/src/nsXMLHttpRequest.cpp
index 03f9d469b50..f9063dba0ff 100644
--- a/mozilla/extensions/xmlextras/base/src/nsXMLHttpRequest.cpp
+++ b/mozilla/extensions/xmlextras/base/src/nsXMLHttpRequest.cpp
@@ -75,6 +75,7 @@
 #include "nsIAuthPrompt.h"
 #include "nsIStringStream.h"
 #include "nsIStreamConverterService.h"
+#include "nsDOMJSUtils.h" // GetScriptContextFromJSContext
 
 static const char* kLoadAsData = "loadAsData";
 #define LOADSTR NS_LITERAL_STRING("load")
diff --git a/mozilla/layout/build/nsLayoutModule.cpp b/mozilla/layout/build/nsLayoutModule.cpp
index 63c1af92e1c..568ce6b8713 100644
--- a/mozilla/layout/build/nsLayoutModule.cpp
+++ b/mozilla/layout/build/nsLayoutModule.cpp
@@ -267,7 +267,9 @@ Initialize(nsIModule* aSelf)
 
   gInitialized = PR_TRUE;
 
-  nsJSEnvironment::Startup();
+  // XXX - should this nsJSRuntime::Startup be changed to a
+  // nsDOMScriptObjectFactory startup, so it can re-init *all* languages?
+  nsJSRuntime::Startup();
   nsresult rv = nsContentUtils::Init();
   if (NS_FAILED(rv)) {
     NS_ERROR("Could not initialize nsContentUtils");
diff --git a/mozilla/modules/oji/src/lcglue.cpp b/mozilla/modules/oji/src/lcglue.cpp
index 1b97dae416c..437b4f964c6 100644
--- a/mozilla/modules/oji/src/lcglue.cpp
+++ b/mozilla/modules/oji/src/lcglue.cpp
@@ -51,6 +51,7 @@
 #include "nsIServiceManager.h"
 #include "nsIScriptSecurityManager.h"
 #include "nsNetUtil.h"
+#include "nsDOMJSUtils.h"
 
 static NS_DEFINE_CID(kJVMManagerCID, NS_JVMMANAGER_CID);
 
diff --git a/mozilla/modules/plugin/base/src/ns4xPlugin.cpp b/mozilla/modules/plugin/base/src/ns4xPlugin.cpp
index 6cbedb524fa..efed83e672c 100644
--- a/mozilla/modules/plugin/base/src/ns4xPlugin.cpp
+++ b/mozilla/modules/plugin/base/src/ns4xPlugin.cpp
@@ -62,6 +62,7 @@
 #include "nsIDocument.h"
 #include "nsIScriptGlobalObject.h"
 #include "nsIScriptContext.h"
+#include "nsDOMJSUtils.h"
 
 #include "nsIXPConnect.h"
 
diff --git a/mozilla/xpcom/base/nsIProgrammingLanguage.idl b/mozilla/xpcom/base/nsIProgrammingLanguage.idl
index 2fe6fb58701..a8f22067165 100644
--- a/mozilla/xpcom/base/nsIProgrammingLanguage.idl
+++ b/mozilla/xpcom/base/nsIProgrammingLanguage.idl
@@ -65,6 +65,9 @@ interface nsIProgrammingLanguage : nsISupports
     const PRUint32 JAVA        = 5;
     const PRUint32 ZX81_BASIC  = 6;  // it could happen :)
     const PRUint32 JAVASCRIPT2 = 7;
+    const PRUint32 RUBY =        8;
+    const PRUint32 TCL =         9;
     // This list can grow indefinitely. Just don't ever change an existing item.
+    const PRUint32 MAX         = 9; // keep this as the largest index.
     
 };
diff --git a/mozilla/xpinstall/src/nsJSInstallTriggerGlobal.cpp b/mozilla/xpinstall/src/nsJSInstallTriggerGlobal.cpp
index bae87db1dfa..5c2984ca218 100644
--- a/mozilla/xpinstall/src/nsJSInstallTriggerGlobal.cpp
+++ b/mozilla/xpinstall/src/nsJSInstallTriggerGlobal.cpp
@@ -51,6 +51,7 @@
 #include "nsIObserverService.h"
 #include "nsInstallTrigger.h"
 #include "nsXPITriggerInfo.h"
+#include "nsDOMJSUtils.h"
 
 #include "nsIComponentManager.h"
 #include "nsNetUtil.h"