Xmonad-conf-jupp0r is a project mainly written in Haskell, it's free.
My XMonad configuration, customized for dvorak keyboard layout and OS X usage
This is my personal XMonad 0.9 configuration, it's optimized for being used to comfortably manage large amounts of terminal windows under OS X. It's based on the config file by Jelle van der Waa ( jelly12gen ), which I found at
http://www.haskell.org/haskellwiki/Xmonad/Config_archive/jelly(12gen)'s_xmonad.hs