More information... I've checked this line in "deploy/jboss-web.deployer/META-INF/jboss-service.xml": | <attribute name="UseJBossWebLoader">false</attribute> | I know, it has nothing to do with the deployment of EAR files, but has made me discover why in another past project I could use "xercesImpl.jar" inside of a web application without conflicts: Because it's using an independent class loader (the one from Tomcat) instead of the JBoss one. So the question now is... Is it impossible to use any library which is already used by JBoss for itself? Will they be in conflict forever? If so, then I guess I'll have to get used to employ the versions used by every version of JBoss and get resigned to it ;) . View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4229572#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...