Something is not clear for me in Chapter 1.5.1. Deployers and ClassLoaders: In the text there is written: Each deployment has a DeploymentInfo instance that has a URLClassLoader pointing to the deployment archive. The DeploymentInfo associated with some.ear is the only one to have a UCL created. The ejbs.jar and web.war DeploymentInfos add their deployment archive to the some.ear UCL classpath, and share this UCL as their deployment UCL. The EJBDeployer also adds any manifest jars to the EAR UCL. For me is the conclusion of this text, that for a ear (except the war) exists only one UCL. But in the Figure 1.20. An illustration of the class loaders involved with an EAR deployment, the some.ear, ejb.jar, web.war are listed seperate and above is written URL Classloaders. What does this mean? Is there now also a UCL for the ejb.jar which is created from the deployment-info? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3999470#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...