From Tribler P2P Research team:
Tribler is a BitTorrent client that doesn't require a tracker for finding content. With content we mean video, audio, pictures, and much more. Tribler has three goals in helping you, the user: Through our improved search functionality you search in content of other Tribler users, and in content of big video web portals such as Youtube and Liveleak. You can browse through different categories as video, audio, or pictures. You can also see what is most popular and what is made available recently. All these functionalities will definitely help you in finding something you like. By making friends and getting in touch with users with similar taste you can find content that you might find interesting. You yourself can also show to your friends what you like and what they definitely should see. Because of the integrated video and audio player you can almost immediately start watching your favorite video(s) or listen to your favorite song(s). Tribler is a social application. This means you can make friends with other users and you can show to everyone what you like and dislike. And by sharing your content you also help other Tribler users to enjoy their favorite content.
What's new in this version:
Version 6.2 includes video on demand option, less disk and CPU consumption, and UI improvements.