Mahout's goal is to build scalable, Apache licensed machine learning libraries. Initially, we are interested in building out the ten machine learning libraries detailed in nips06-mapreducemulticore.pdf using Hadoop. While these algorithms are our initial focus, we welcome contributions of other machine learning approaches.
Interested in helping? See the Wiki or send us an email. Also note, we are just getting off the ground, so please be patient as we get the various infrastructure pieces in place.