Leaving old JARs in the WEB-INF/lib directory would not be an issue - if those classes are not used then all the file is doing is taking up disk space. Of course, that tactic fails if you do something like combine all of the classes in one.jar and two.jar into one-two.jar. Then you would have one.jar, two.jar and one-two.jar in WEB-INF/lib which is guaranteed to be a mess. I imagine you could code up you own classloading to load the client's custom JAR file so that file could be located anywhere, but that seems like a lot of work and fairly error prone. Some kind of deployment strategy seems easier to me, even if it is that you supply your customers with a deployer (which could be a script file) that does what you mentioned. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4217205#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...