Ah yes. Now I get it. In my last post I opined that it was most annoying to need to wrap all third party libraries in a plug-in if I expected the Eclipse RCP to see them (specifically Hibernate and Log4J). OK, after reading and digesting the OSGi explaination (http://wiki.eclipse.org/index.php/Context_Class_Loader_Enhancements) all becomes clear. In fact, I was able to set up both the Hibernate and Log4J in the same plug in in about 5 minutes. Amazing once you know what you are doing. Just to help out, I'll go through the full procedure for those who are interested in my next post.