This is a portable BitTorrent client with basic features along with support for extensions. The most recent release (14-oct-2013) is 0.4.3 for Windows, Debian 6.0.6, Ubuntu 12.04 and OSX 10.6.8.

Only one extension is available so far: a simple server that is compatible with how the uTorrent WebUI adds torrents. Therefore, Firefox extensions such as BitTorrent WebUI++ work fine for adding torrents.