Deluge is a lightweight, free, cross-platform BitTorrent client. It uses libtorrent in it´s backend and PyGTK for it´s user interface.

Deluge features a rich plugin collection; in fact, most of Deluge´s functionality is available in the form of plugins. Deluge was created with the intention of being lightweight and unobtrusive.

Features:

• Web UI
• BitTorrent Protocol Encryption
• Mainline DHT
• Local Peer Discovery (aka LSD)
• FAST protocol extension
• µTorrent Peer Exchange
• UPnP and NAT-PMP
• Proxy support
• Web seed
• Private Torrents
• Global and per-torrent speed limits
• Configurable bandwidth scheduler
• Password protection
• RSS
• And much more!

Linux and Mac OS X versions of Deluge are available at the developer´s website.