Transmission is a bittorrent client for Linux, Mac, and BSD.
I like to have Transmission start on login with lowered priority and minimized to the notification area; the command for this on Linux is nice transmission-gtk -m.
In Linux, Transmission’s per-user files are found at ~/.config/transmission/. I back up:
settings.json is small but frequently changes, so you might consider excluding it from sync-based backups and backing it up via other means.
ALTERNATIVES TO TRANSMISSION
If Transmission doesn’t make you happy, there are other bittorrent clients.
These notes refer to Transmission 2.50 on Linux and were last updated 16 September 2012.