Transmission is a free, lightweight BitTorrent client. It features a simple, intuitive interface on top on an efficient, cross-platform back-end. Transmission has the features you want from a BitTorrent client: encryption, a web interface, peer exchange, magnet links, DHT, uTP, UPnP and NAT-PMP port forwarding, webseed support, watch directories, tracker editing, global and per-torrent speed limits, and more.