KTorrent is a BitTorrent filesharing program for KDE.
Here are some key features of "KTorrent":
ˇ Downloads torrent files
ˇ Upload speed capping, seeing that most people can't upload infinite amounts of data.
ˇ Internet searching using The Bittorrent website's search engine
ˇ UDP Trackers
It has only been tested on linux at the moment, but it should work on most, if not all unix platforms.