In my opinion the main issue with OSGi class loading is that the spec couples three separate concerns: peer class loading (as opposed to hierarchical) depende

In my opinion the main issue with OSGi class loading is that the spec couples three separate concerns: peer class loading (as opposed to hierarchical) dependency resolution dependency specification and module (bundle) packaging This makes OSGi an all or nothing solution: to use OSGi class loading you are forced to package your code in a specific way - which in turn makes it difficult to reuse existing libraries. Lack of peer class loading has been a long standing pain point in Java - and in my opinion one of the main obstacles for really interesting use cases - especially related to mobile code ( see Jini ).