This has been committed to 4.2 and 5.0. It doesn't look at the web.xml version. It should be legal to run a 2.4 web.xml with the built-in JSF impl. It would go against the JEE5 spec if we required a JSF impl in the war for that. Instructions for using this new feature are at the bottom of this wiki: http://wiki.jboss.org/wiki/Wiki.jsp?page=JBoss5AndMyFaces This feature is "community only" and not "officially supported". To explain that, if you are a JBoss/Red Hat support customer we will only support the built-in version of JSF. We always do our best to help our support customers even when they use non-standard libraries. But we can't give any sort of guarantee when a customer uses their own JSF implementation. Stan View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4042071#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...