diff --git a/proposal/myrmidon/src/java/org/apache/myrmidon/components/builder/DefaultProjectBuilder.java b/proposal/myrmidon/src/java/org/apache/myrmidon/components/builder/DefaultProjectBuilder.java
index 7cbe0e709..e8f92a6e1 100644
--- a/proposal/myrmidon/src/java/org/apache/myrmidon/components/builder/DefaultProjectBuilder.java
+++ b/proposal/myrmidon/src/java/org/apache/myrmidon/components/builder/DefaultProjectBuilder.java
@@ -15,8 +15,11 @@ import javax.xml.parsers.SAXParser;
 import javax.xml.parsers.SAXParserFactory;
 import org.apache.avalon.excalibur.i18n.ResourceManager;
 import org.apache.avalon.excalibur.i18n.Resources;
+import org.apache.avalon.framework.CascadingException;
 import org.apache.avalon.framework.ExceptionUtil;
+import org.apache.avalon.framework.Version;
 import org.apache.avalon.framework.configuration.Configuration;
+import org.apache.avalon.framework.configuration.ConfigurationException;
 import org.apache.avalon.framework.configuration.SAXConfigurationHandler;
 import org.apache.avalon.framework.logger.AbstractLogEnabled;
 import org.apache.myrmidon.components.model.DefaultProject;
@@ -39,6 +42,8 @@ public class DefaultProjectBuilder
     private static final Resources REZ =
         ResourceManager.getPackageResources( DefaultProjectBuilder.class );
 
+    private final static Version VERSION = new Version( 2, 0, 0 );
+
     private final static int PROJECT_REFERENCES = 0;
     private final static int LIBRARY_IMPORTS = 1;
     private final static int IMPLICIT_TASKS = 2;
@@ -124,6 +129,14 @@ public class DefaultProjectBuilder
         //get project-level attributes
         final String baseDirectoryName = configuration.getAttribute( "basedir", null );
         final String defaultTarget = configuration.getAttribute( "default", "main" );
+        final Version version = getVersion( configuration );
+
+        if( !VERSION.complies( version ) )
+        {
+            final String message =
+                REZ.getString( "ant.bad-version.error", VERSION, version );
+            throw new Exception( message );
+        }
 
         //determine base directory for project.  Use the directory containing
         //the build file as the default.
@@ -148,6 +161,45 @@ public class DefaultProjectBuilder
         return project;
     }
 
+    /**
+     * Retrieve the version attribute from the specified configuration element.
+     * Throw exceptions with meaningful errors if malformed or missing.
+     */
+    private Version getVersion( final Configuration configuration )
+        throws CascadingException
+    {
+        try
+        {
+            final String versionString = configuration.getAttribute( "version" );
+            return parseVersion( versionString );
+        }
+        catch( final ConfigurationException ce )
+        {
+            final String message = REZ.getString( "ant.version-missing.error" );
+            throw new CascadingException( message, ce );
+        }
+    }
+
+    /**
+     * Utility function to extract version
+     */
+    private Version parseVersion( final String versionString )
+        throws CascadingException
+    {
+
+        try
+        {
+            return Version.getVersion( versionString );
+        }
+        catch( final Exception e )
+        {
+            final String message =
+                REZ.getString( "ant.malformed.version", versionString );
+            getLogger().warn( message );
+            throw new CascadingException( message, e );
+        }
+    }
+
     /**
      * Handle all top level elements in configuration.
      *
diff --git a/proposal/myrmidon/src/java/org/apache/myrmidon/components/builder/Resources.properties b/proposal/myrmidon/src/java/org/apache/myrmidon/components/builder/Resources.properties
index c0ff96a6e..63e387bed 100644
--- a/proposal/myrmidon/src/java/org/apache/myrmidon/components/builder/Resources.properties
+++ b/proposal/myrmidon/src/java/org/apache/myrmidon/components/builder/Resources.properties
@@ -23,3 +23,6 @@ ant.target-noname.error=Discovered un-named target at {0}.
 ant.target-bad-name.error=Target with an invalid name at {0}.
 ant.target-bad-logic.error=Discovered invalid target that has both a if and unless condition at {0}.
 ant.target-bad-dependency.error=Discovered empty dependency in target {0} at {1}.
+ant.malformed.version=Malformed version string "{0}" specified in version attribute of project.
+ant.version-missing.error=Missing version attribute from project.
+ant.bad-version.error=Incompatible build file version detected. Expected {0} but found {1}.
diff --git a/proposal/myrmidon/src/make/primitive-tests.ant b/proposal/myrmidon/src/make/primitive-tests.ant
index f4b3e28bf..a59df484e 100644
--- a/proposal/myrmidon/src/make/primitive-tests.ant
+++ b/proposal/myrmidon/src/make/primitive-tests.ant
@@ -14,7 +14,7 @@ Legal:
 ==============================================================================
 -->
 
-<project name="MySample" default="main" basedir=".">
+<project version="2.0.0">
 
   <import library="selftest" />
 
@@ -58,8 +58,7 @@ Legal:
         float="1.0"
         float2="2.0"
         double="3.0"
-        double2="4.0"
-     />
+        double2="4.0" />
 
     <sub-elements-test>
       <create-beep message="A string" />
diff --git a/proposal/myrmidon/src/make/sample.ant b/proposal/myrmidon/src/make/sample.ant
index bd6d645cc..ebd4e4c8d 100644
--- a/proposal/myrmidon/src/make/sample.ant
+++ b/proposal/myrmidon/src/make/sample.ant
@@ -14,7 +14,7 @@ Legal:
 ==============================================================================
 -->
 
-<project name="MySample" default="main" basedir=".">
+<project version="2.0.0">
 
   <projectref name="prim" location="primitive-tests.ant" />