Tribler!

µTorrent is a lightweight BitTorrent client that includes standard features such as bandwidth prioritization, scheduling, RSS auto-downloading and Mainline DHT. Additionally, µTorrent supports the Protocol Encryption joint specification and peer exchange.

Deluge is a full-featured BitTorrent client for Linux, Unix and Windows. It is written in python, uses libtorrent (rasterbar) at its core and GTK for the main user interface along with web and console interfaces for advanced client/server facility.

Tixati is a peer-to-peer file sharing program that uses the popular BitTorrent protocol. This protocol allows many peers to form a cooperative swarm and download very large files with great efficiency.

RetroShare is a open source cross-platform, private and secure decentralized communication system. It lets you to securely chat, share photos, videos, and more, using OpenPGP to authenticate peers and OpenSSL to encrypt all communication.

Using WebRTC, FilePizza eliminates the initial upload step required by other web-based file sharing services. When senders initialize a transfer, they receive a "tempalink" they can distribute to recipients. Upon visiting this link, recipients' browsers connect directly to the sender’s browser and may begin downloading the selected file. Because data is never stored in an intermediary server, the transfer is fast, private, and secure.

rtorrent is a BitTorrent client for ncurses, using the libtorrent library. The client and library is written in C++ with emphasis on speed and efficiency, while delivering equivalent features to those found in GUI based clients in an ncurses client.

PicoTorrent is a tiny BitTorrent client for Windows with low memory usage, high performance and a native user interface. No ads, carefully selected features, and a native user interface integrating seamlessly with your desktop.

KTorrent is a bittorrent application for KDE which allows you to download files using the BitTorrent protocol. It enables you to run multiple torrents at the same time and comes with extended features to make it a full-featured client for BitTorrent. KTorrent offers advanced configuration options, plenty of features and a wealth of useful plugins, like the Search plugin which will allow you to search for torrents directly from within KTorrent.

BiglyBT is a feature filled, open source, bittorrent client based on the Azureus open source project, now Vuze .

CuteTorrent is a lightweight BitTorrent client with a simple, intuitive interface designed to quickly download and share torrent files. At the heart of it’s core resides the powerful libtorrent BitTorrent library.

BitComet is a BitTorrent/HTTP/FTP download management software, which is powerful, and easy-to-use. It contains many advanced features that can accelerate your downloading up to 5 - 10 times faster, or even more.

Anomos is a pseudonymous, encrypted multi-peer-to-peer file distribution protocol. It is based on the peer/tracker concept of BitTorrent in combination with an onion routing anonymization layer, with the added benefit of end-to-end encryption. By combining these technologies, we have created a platform where by no party outside of the trusted tracker will have any information about who a peer is or what they are downloading.