Uses what appears to be currently stable commit, 6068a1fab883ed9254bfeb53a1f9c15e8af0bb20 dated Oct 22, 2010, which updates tagged release 0.2a. I've thus named the opam package froc.0.2.2 following the logic that the tagged 0.2 and 0.2a releases are 0.2.0 and 0.2.1 respectively.