WebTorrent Desktop is fast, free, non-commercial & open source.

What is WebTorrent?

WebTorrent is written completely in JavaScript – the language of the web – and uses WebRTC for peer-to-peer transport whenever possible. No browser plugins, extensions, or installation is required to use WebTorrent in your browser.

connects to both BitTorrent and WebTorrent peers.

WebTorrent Desktop

It can talk to peers running Transmission or uTorrent, and it can also talk to web pages like instant.io.