Computers, Programming, Languages, Logic-based - The Maude System. Maude is a reflective language based on equational rewrite principles, useful for modeling and solving a wide range of computational problems.
Computers, Programming, Languages, Logic-based - XSB. A research-oriented Logic Programming system for Unix and Windows/DOS-based systems, representing a semantically enriched functional superset of Prolog and offering among other things evaluation through full SLG resolution.