BitTorrent is a popular P2P file protocol that requires no central server.

Current version: 3.4, released on 2004-03-06. This is a bug fix and performance release. Everyone running large trackers should upgrade and encourage all of their users to upgrade New in 3.4:

Client no longer complains of connection to tracker problems when transfers are still working
Lots of bandwidth savings
Lots of bug fixes

Download BitTorrent 3.4