FrostWire!

The qBittorrent project aims to provide a Free Software alternative to µtorrent. Additionally, qBittorrent runs and provides the same features on all major platforms (Linux, Mac OS X, Windows, OS/2, FreeBSD).

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.

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.

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.

MLDonkey is an open source, multi-protocol, peer-to-peer file sharing application that runs as a back-end server application on many platforms. It can be controlled through a user interface provided by one of many separate front-ends, including a Web interface, telnet interface and over a dozen native client programs.Its great when you have multple computers and you want to set up one server to download and in multiple computers with multiple users you can add files. (use it with Sancho Gui)

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.