According to the JAX-RS spec it should be possible to deploy a war with multiple application classes. While attempting to resolve AS7-3199 I noticed that RESTeasy stashes some stuff in the servlet context, which then gets mixed up between the different servlets:

https://github.com/resteasy/Resteasy/blob/master/jaxrs/resteasy-jaxrs/src/main/java/org/jboss/resteasy/plugins/server/servlet/ServletContainerDispatcher.java#L69

To see the code I am using to run this: https://github.com/stuartwdouglas/jboss-as/compare/AS7-3199 . MultipleApplicationTestCase fails randomly, depending on the order that that application is initialised.