Packages are available for 11.10 (Oneiric Ocelot), 12.04 (Precise Pangolin), 12.10 (Quantal Quetzal), 13.04 (Raring Ringtail), 13.10 (Saucy Salamander), and 14.04 (Trusty Tahr).
sudo apt-add-repository ppa:tycho-s/ppa
sudo apt-get update
sudo apt-get install qtile