I should have said that I tried to use the (left angle bracket) classpath (right angle bracket) element in jboss-4.0.5/server/myServer/conf/jboss-service.xml. I put in three such elements, like this: | <classpath codebase="${jboss.server.lib.url:lib}" archives="shadow.jar"/> | <classpath codebase="${jboss.server.lib.url:lib}" archives="base.jar"/> | <classpath codebase="${jboss.server.lib.url:lib}" archives="*"/> | I would think that would make it so that the various JBoss classloaders in effect would get Foo.class from shadow.jar, not base.jar. I have reports from users that this is not consistent across systems, which makes me think that this is not the way to do it. Also, in the case of a web application deployed later on, will it--when its loader comes up to this parent in search of Foo.class--will the parent loader in such a case respect this order? The mind-bending diagram in the classloader use cases topic would appear to say yes, this is the case, but that's not the behavior being seen. Finally, if in my code I ask a UCL for its URLs, I take it their order is absolutely and entirely insignificant, and that it is actually impossible to tell who will load a given class. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4056609#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...