Much of the code from the software engineering work in our group is available via our GitHub group on Machine Learning for Source Code Text.
I have contributed to MALLET, a Java package for machine learning on text. MALLET includes implementations of several classification algorithms, conditional random fields, and latent Dirichlet allocation.
I have also written GRMM, a Java toolkit for inference in graphical models with discrete variables. It includes facilities for easily constructing and training CRFs with arbitrary graphical structure. I have used it to produce results for several of my papers, including those on DCRFs and skip-chain CRFs.
For more “fun” projects (not that fun, sorry), see my Github page.
Maybe you’re particularly interested in the source for this site.
I enjoy playing around with “productivity” software.