As of JBossRemoting 2.0.0 versioning has been added to guarantee compatibility between different versions. This is accomplished by changing serialization formats for certain classes and by using wire versioning. By wire versioning, mean that the version used by a client and server will be sent on the wire so that the other side will be able to adjust accordingly. This will be automatic for JBossRemoting 2.0.0 and later versions. However, since versioning was not introduced until the 2.0.0 release, if need to have a 1.4.x version of remoting communicate to a later version, will need to set a system property on the 2.0.0 version so that knows to use the older wire protocol version. The system property to set is 'jboss.remoting.pre_2_0_compatible' and should be set to true. There are a few minor features that will not be fully compatible between 1.4.x release and 2.0.0, which are listed in the release notes.