diff --git a/plugin/plugin.jelly b/plugin/plugin.jelly
index ab2f6e55..77239bda 100644
--- a/plugin/plugin.jelly
+++ b/plugin/plugin.jelly
@@ -369,6 +369,67 @@
         </ant:fileset>
       </ant:delete>
     </define:tag>
+    
+  <define:tag name="available">
+    <!-- Check parameters -->
+    <maven:param-check value="${groupId}" fail="true" message="'groupId' must be specified"/>
+    <maven:param-check value="${artifactId}" fail="true" message="'artifactId' must be specified"/>
+    <maven:param-check value="${minRelease}" fail="true" message="'minRelease' must be specified"/>
+    
+    <j:set var="pluginToTest" value="${artifactId}"/>
+    <j:set var="minReleaseToHave" value="${minRelease}"/>
+
+    <maven:get plugin="${pluginToTest}" property="plugin" var="installedPlugin" />
+    <!-- Check if the plugin is installed -->
+    <j:choose>
+      <j:when test="${!empty(installedPlugin)}">
+        <j:set var="installedRelease" value="${installedPlugin.currentVersion}"/>
+        <!-- Remove SNAPSHOT -->
+        <u:replace var="installedRelease" escapeText="true" old="-SNAPSHOT" new="">${installedRelease}</u:replace>
+        <u:replace var="minReleaseToHave" escapeText="true" old="-SNAPSHOT" new="">${minReleaseToHave}</u:replace>
+        <!-- Tokenify -->
+        <u:tokenize var="installedReleaseTokens" delim="." escapeText="true">${installedRelease}</u:tokenize>
+        <u:tokenize var="minReleaseToHaveTokens" delim="." escapeText="true">${minReleaseToHave}</u:tokenize>
+        <j:set var="minReleaseToHaveTokensIter" value="${minReleaseToHaveTokens.iterator()}"/>
+        
+        <j:forEach var="numberInstalled" items="${installedReleaseTokens}">
+          <j:if test="${!minReleaseToHaveTokens.iterator().hasNext()}">
+            <j:set var="testFailed" value="true"/>
+            <j:break/>
+          </j:if>
+          <j:set var="numberToHave" value="${minReleaseToHaveTokensIter.next()}"/>
+          <j:choose>
+              <j:when test="${numberInstalled.compareTo(numberToHave) lt 0}">
+                <!-- ${numberInstalled} is less than ${numberToHave} => fail -->
+                <j:set var="testFailed" value="true"/>
+                <j:break/>
+              </j:when>
+              <j:when test="${numberInstalled.compareTo(numberToHave) eq 0}">
+              <!-- ${numberInstalled} is equal than ${numberToHave} => continue to test -->
+              </j:when>
+              <j:when test="${numberInstalled.compareTo(numberToHave) gt 0}">
+              <!-- ${numberInstalled} is greater than ${numberToHave} => good -->
+                <j:break/>
+              </j:when>              
+          </j:choose>
+        </j:forEach> 
+      </j:when>
+      <j:otherwise>
+        <j:set var="testFailed" value="true"/>
+      </j:otherwise>
+    </j:choose>
+
+    <j:if test="${testFailed}">
+      <ant:fail>
+      - BE CAREFUL
+      =======================================================================================
+      Must have ${pluginToTest} plugin v${minReleaseToHave} installed to use this version of the plugin.
+      Try: maven plugin:download -DgroupId=maven -DartifactId=${pluginToTest} -Dversion=${minReleaseToHave}
+      =======================================================================================
+      </ant:fail>
+    </j:if>
+  </define:tag>    
+    
   </define:taglib>
     
   <define:taglib uri="assert">
diff --git a/plugin/xdocs/changes.xml b/plugin/xdocs/changes.xml
index ae3e6e42..9e12e8e5 100644
--- a/plugin/xdocs/changes.xml
+++ b/plugin/xdocs/changes.xml
@@ -23,6 +23,9 @@
     <author email="evenisse@ifrance.com">Emmanuel Venisse</author>
   </properties>
   <body>
+    <release version="1.7-SNAPSHOT" date="In SVN">
+      <action dev="aheritier" type="add">new plugin:available tag to check if a minimal release of a plugin is present.</action>
+    </release>
     <release version="1.6" date="2005-06-03">
       <action dev="vmassol" type="add">Added new
         <code>assert:assertFileContains</code>tag that verifies if a file contains a specific string.
diff --git a/plugin/xdocs/tags.xml b/plugin/xdocs/tags.xml
index 33bc4c4c..9275eea0 100644
--- a/plugin/xdocs/tags.xml
+++ b/plugin/xdocs/tags.xml
@@ -31,6 +31,7 @@
           <ol>
             <li><a href='#uninstall_Tag'>uninstall</a></li>
             <li><a href='#clearCache_Tag'>clearCache</a></li>
+            <li><a href='#available_Tag'>available</a></li>
           </ol>
         </li>
         <li><a href='#assert_Tag_Library'>assert</a>
@@ -70,6 +71,27 @@
         </p>
         <p>There are no attributes for this tag</p>
       </subsection>
+      <subsection name='assertFileExists Tag'>
+        <p>Fails the build if the given plugin does not exist or hasn't the minimal release number. Otherwise no effect.</p>
+        <table>
+          <tr><th>Attribute</th><th>Optional?</th><th>Description</th></tr>
+          <tr>
+            <td>groupId</td>
+            <td>No</td>
+            <td>The plugin's groupId</td>
+          </tr>
+          <tr>
+            <td>artifactId</td>
+            <td>No</td>
+            <td>The plugin's artifactId</td>
+          </tr>
+          <tr>
+            <td>minRelease</td>
+            <td>No</td>
+            <td>The minimum plugin's release</td>
+          </tr>
+        </table>
+      </subsection>
     </section>
     <section name='assert Tag Library'>
       <p>

Attribute	Optional?	Description
groupId	No	The plugin's groupId
artifactId	No	The plugin's artifactId
minRelease	No	The minimum plugin's release