Deluge BitTorrent client with multiple interfaces, password protection and plugins

Deluge is a free  BitTorrent client, featuring multiple user-interfaces including: GTK+, web and console, as well as 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, since downloading usually is not the primary task on a computer and therefore it shouldn’t monopolize system resources.

Features: Core/UI split allowing Deluge to run as a daemon * Connect remotely to the Deluge daemon * Web UI * Console UI * GTK+ 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 (via Plugin).

If you are going to try Deluge after some other BitTorrent client, just configure it to use for its downloads the folder you already use, and it will re-load whatever you have downloaded and continue to finish. Yet, you need to add the torrents yourself from .torrent files or urls.