With the release of version 3.1, WinMX is easily the best PTP file sharing program out there right now. Since Morpheus switched from the Fast Track protocol to a gnutella protocol several months ago it sucks. It's not worth bothering with. Kaza still uses the fast track protocol but it installs a lot of "spyware" on your computer so I would advise against using it. Stick with WinMX, it has an incredibly large user base and uses a distributed protocol so it would be very difficult to shut down.