Off topic (but I thought you guy might want to know), but the FastTrack protocol has been nearly deciphered, clearing the way for third party KaZaA/Morpheus/Grokster clones on a variety of platforms.

The project under this is giFT, or the generic interface to fasttrack. Since the FastTrack protocol is so complicated (encrypted everywhere), graphical frontends use giFT as a daemon and talk xml with it, making client development _very_ easy (downloads are also just http-based).

webpage is http://gift.sourceforge.net/