KTorrent

KTorrent is a BitTorrent program for KDE. The current release is 2.1rc1 which is the second release on the way to the final 2.1 release. New features added since 2.0.3 :

-µTorrent compatible peer exchange
-Zeroconf extension to find peers on the local network
-Switched the GUI to an IDEAl style GUI (like KDevelop)
-WebGUI plugin
-RSS plugin
-Improvements in down and upload performance
-Grouping feature to put torrents into groups
-Improved search plugin, which now allows multiple searches
-Many bug fixes

And of course a whole bunch of bug fixes. We allready supported the following features in the previous version :

-Downloads torrent files
-Upload and download speed capping
-Internet searching using various search engines, you can even add your own
-UDP Trackers
-Port forwarding with UPnP
-IP blocking plugin
-Importing of partially or fully downloaded files
-Support for distributed hash tables (mainline version)
-Protocol encryption
-Bandwith scheduling
-Directory scanner to automatically load torrents in certain directories
-Trackers can now be added to torrents
-File prioritization for multi file torrents

It has only been tested on linux at the moment, but it should work on most, if not all unix platforms. The latest stable version of ktorrent is 2.1rc1 and it's released under the GNU GPL License.