LIBSVM: a simple and easy-to-use support vector machines tool for classification (C-SVC, nu-SVC), regression (epsilon-SVR, nu-SVR), and distribution estimation.
It includes a GUI for both classification and regression. Version 1.0 released in April 2000. Current Version: 3.17, April 2013.
See software document published in ACM TIST: pdf, ps.gz, ACM digital lib.
LIBLINEAR: a library for large linear classification. It is very suitable for document classification. Version 1.0 released in April 2007. Current Version: 1.93, January 2013.
LibShortText: a library for short-text classification and analysis. Version 1.0 released in February 2013. Current Version: 1.0, February 2013.