Mahout currently has Collaborative Filtering User and Item based recommenders K-Means, Fuzzy K-Means clustering Mean Shift clustering Dirichlet process clustering Latent Dirichlet Allocation Singular value decomposition Parallel Frequent Pattern mining Complementary Naive Bayes classifier Random forest decision tree based classifier High performance java collections (previously colt collections) A vibrant community and many more cool stuff to come by this summer thanks to Google summer of code
What's Torch ?
It's a machine-learning library, written in simple C++ and distributed now under a BSD license.
Torch is currently developed at IDIAP, in Switzerland mountains.
Lush is an object-oriented programming language designed for researchers, experimenters, and engineers interested in large-scale numerical and graphic applications.