XOMaster is a fairly strong AI five in a row (free-style gomoku) player. It implements a simple interface and an alpha-beta search function with a fast eval function.
A fast decision tree program featuring distributed ensemble learning across multiple processors using MPI. Has been run on 1 cpu, small clusters, and the ASCI Blue supercomputer. Ensembles are often more accurate than their single classifier counterparts
VFML -- Very Fast Machine Learning toolkit. A collection of tools, learners, and APIs for working with high-speed data streams and very large data sets.