daemon:
https://bbs.archlinux.org/viewtopic.php?id=53395
http://kmandla.wordpress.com/2009/05/28/running-rtorrent-as-a-daemon/
in background
http://wiki.awkwardtv.org/wiki/index.php?title=How_to_run_rTorrent_as_a_background_process_using_dtach&redirect=no
http://www.linuxquestions.org/questions/linux-software-2/rtorrent-how-to-make-it-run-in-the-background-596041/
setup
https://wiki.archlinux.org/index.php/RTorrent
http://libtorrent.rakshasa.no/
https://calomel.org/rtorrent_mods.html
http://kmandla.wordpress.com/2007/05/02/howto-use-rtorrent-like-a-pro/
http://ditoinfo.wordpress.com/2007/06/05/howto-use-rtorrent-to-download-torrents/
http://alinuxblog.wordpress.com/2008/10/05/top-5-torrent-clients-for-linux/
http://www.cyberciti.biz/tips/linux-command-line-bittorrent-client.html