Actually you shouldn't have to download anything at all. As of JBoss 4.0.2SP1, the hibernate libraries are stored in //server/default/lib/hibernate*.jar. So change your build.xml to reference that lib directory (instead of the non-existent directory it's currently referencing) or copy the jar over to your compile-lib directory. (source: http://www.oreilly.com/catalog/jboss/errata/jboss.confirmed) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3996988#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...