We just released version 0.1 of cofirank, the implementation of our algorithm of the same name.
CofiRank (the algorithm) is one of the very few that can predict the actual ranking of items a user may like as opposed to the rating computed by the vast majority of recommender systems. We have discussed the algorithm in a NIPS-Paper.
CofiRank (the implementation) is rather efficient, it can be trained on the well known Netflix data set with less than 2GB memory on a standard laptop. Go check it out and comment here with your findings ;)