Active networks allow code to be loaded dynamically into network nodes at runtime. This code can perform tasks specific to a stream of packets or even a single packet. In this talk we compare two active network architectures: the Active Network Transfer System (ANTS) and the Messenger System (M0). We have implemented a robust audio multicast protocol and a layered video multicast protocol with both active network systems. We discuss the differences of the two systems, evaluate architectural strengths and weaknesses, compare the runtime performance, and report practical experience and lessons learned.