In separate benchmarks, Linux Format and Lacrocivious both found Transmission to use less CPU than any other GUI client. When Ubuntu chose Transmission as its default BitTorrent client, one of the most-cited reasons was its easy learning curve. We've set the defaults to Just Work and it only takes a few clicks to configure advanced features like watch directories, bad peer blocklists, and the web interface. Transmission is designed for easy, powerful use. Unlike some BitTorrent clients, Transmission doesn't play games with its users to make money: Transmission is an open source, volunteer-based project.
Transmission is a cross-platform BitTorrent client that is: Open Source.