"jshowalter" wrote : Okay, I found the docs. I've ported our code. Now we need to deploy it into production, which is using Jboss 4.3.CP02 (and not easily changed). Will we be able to do that, or are the versions too different to be compatible? Depends. You cannot upgrade the versions of JBC that the app server uses for its own clustering code, but if you isolate class loaders, you can package newer JBC versions in your app and use it. Read this doc for details: http://www.jboss.org/community/docs/DOC-10254 View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4212868#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...