Application and desktop sharing allows sharing of any application with one or more people over the Internet. The participants receive the screen-view of the shared application from the server. Their mouse and keyboard events are delivered and regenerated at the server. Application and desktop sharing enables collaborative work, software tutoring, and e-learning over the Internet. We have developed an application and desktop sharing platform called BASS which is efficient, reliable, independent of the operating system, scales well via heterogenous multicast, supports all applications, and features true application sharing.