OpenRefine (formerly Google Refine) is a free, open-source tool for working with messy data. It enables users to clean data, transform it between a variety of formats, extend it with web services, and link it to databases. This tool is available for Windows, Mac and Linux.

Weka provides machine learning algorithms in Java for data mining and predictive modeling tasks. These algorithms can either be incorporated into other Java code or called from the Weka Workbench, a GUI environment.