PI Steve Chong, former visiting scholar and collaborator Marco Gaboardi, and graduate student Aaron Bembenek have research AbcDatalog. AbcDatalog is an open-source Datalog engine implemented in Java. It provides ready-to-use implementations of common Datalog evaluation algorithms, including efficient multi-threaded versions of bottom-up and magic set transformation techniques.
More details are available on the AbcDatalog webpage: http://abcdatalog.seas.harvard.edu/.