Download and compile libtorrent
sudo wget http://libtorrent.rakshasa.no/downloads/libtorrent-0.12.6.tar.gz
sudo tar zxfv libtorrent-0.12.6.tar.gz
cd libtorrent-0.12.6
sudo ./configure
sudo make
sudo make install
Download and compile xmlrpc-c
sudo svn checkout http://xmlrpc-c.svn.sourceforge.net/svnroot/xmlrpc-c/stable xmlrpc-c
cd xmlrpc-c/
sudo ./configure
sudo make
sudo make install
Download and compile rtorrent
sudo wget http://libtorrent.rakshasa.no/downloads/rtorrent-0.8.6.tar.gz
sudo tar zxfv rtorrent-0.8.6.tar.gz
cd rtorrent-0.8.6
sudo ./configure --with-xmlrpc-c
sudo make
sudo make install