Archimedes Rules Repository - an Open Source tool for Developers, Project Managers, and Business Analysts.
Archimedes provides reporting on existing rule objects: Example: object artifact inventory, statistical analysis, metrics,and detailed HTML reports.(Like JavaDoc for your business rules!)
MetaRepos an Open Source Metadata Repository Model. This is anapplication that is used by Archimedes to persist business rules and metadata to the database using REST services. It also can provide transformations between repository models.
MetaRepos ships with HTML and Java front-end applications to explore business rules, data objects, metadata, and compare differences between repository versions.