CLIPS

CLIPS (C Language Integrated Production System) is a public-domain software tool for building expert systems. The syntax and name were inspired by Charles Forgy's OPS5. The first versions of CLIPS were developed starting in 1985 at the NASA Johnson Space Center (as an alternative for existing system ART*Inference) until 1996, when the development group's responsibilities ceased to focus on expert system technology. The original name of the project was ''NASA's AI Language'' (NAIL).

As of 2005, CLIPS was probably the most widely used expert system tool. CLIPS is written in C, extensions can be written in C, and CLIPS can be called from C. Its syntax resembles that of the programming language Lisp.

CLIPS incorporates a complete object-oriented programming language for writing expert systems. COOL combines the programming paradigms of procedural, object oriented, and logic programming (automated theorem proving) languages. Provided by Wikipedia