CLIPS is a public-domain software tool for building expert systems. The name is an acronym for "C Language Integrated Production System." The syntax and name was inspired by Charles Forgy's OPS ("Official Production System," although there was nothing really official about it). The first versions of CLIPS were developed starting in 1985 at NASA-Johnson Space Center (as an alternative for existing system ART*Inference) until the mid 1990s when the development group's responsibilities ceased to focus on expert system technology. The public domain comprises the body of all creative works and other knowledge—writing, artwork, music, science, inventions, and others—in which no person or organization has any proprietary interest. ... An expert system is a class of computer programs developed by researchers in artificial intelligence during the 1970s and applied commercially throughout the 1980s. ... Wikibooks has a book on the topic of C Programming The C programming language (often, just C) is a general-purpose, procedural, imperative computer programming language developed in the early 1970s by Dennis Ritchie for use on the Unix operating system. ... Charles L. Forgy is a computer scientist, notable for developing the Rete algorithm used in his OPS5 and other production system languages used to build expert systems. ... OPS5 is a rule-based or production system computer language, notable as the first such language to be used in a successful expert system, the R1/XCON system used to configure VAX computers. ... Year 1985 (MCMLXXXV) was a common year starting on Tuesday (link displays 1985 Gregorian calendar). ... The National Aeronautics and Space Administration (NASA) is an agency of the United States government, responsible for the nations public space program. ... An aerial view of the complete Johnson Space Center facility in Houston, Texas in 1989. ... For the band, see 1990s (band). ...

CLIPS is probably the most widely used expert system tool because it is fast, efficient and free. Although it is now in the public domain, it is still updated and supported by the original author, Gary Riley. CLIPS incorporates a complete object-oriented language COOL for writing expert systems. Though it is written in C, its interface more closely resembles that of the programming language LISP. Extensions can be written in C, and CLIPS can be called from C. Object-oriented programming (OOP) is a programming paradigm that uses objects to design applications and computer programs. ... Wikibooks has a book on the topic of C Programming The C programming language (often, just C) is a general-purpose, procedural, imperative computer programming language developed in the early 1970s by Dennis Ritchie for use on the Unix operating system. ... A programming language is an artificial language that can be used to control the behavior of a machine, particularly a computer. ... For the programming language, see Lisp (programming language). ...

Like other expert system languages, CLIPS deals with rules and facts. Various facts can make a rule applicable. An applicable rule is then asserted. Facts and rules are created by first defining them, as shown below:

 (deffacts trouble_shooting (car_problem (name ignition_key) (status on)) (car_problem (name engine) (status wont_start)) (car_problem (name headlights) (status work)) ) (defrule rule1 (car_problem (name ignition_key) (status on)) (car_problem (name engine) (status wont_start)) => (assert (car_problem (name starter) (status faulty)) ) 

Descendants of the CLIPS language include Jess (rule-based portion of CLIPS rewritten in Java, it later grew up in different direction), Haley Eclipse, FuzzyCLIPS (which adds concept of relevancy into the language) and others. Jess, a rule engine for the Java platform, is a superset of CLIPS programming language, developed by Ernest Friedman-Hill of Sandia National Labs. ... Java is a programming language originally developed by Sun Microsystems and released in 1995. ... FuzzyCLIPS is a fuzzy logic extension of the CLIPS (C Language Integrated Production System) expert system shell from NASA. It was developed by the Integrated Reasoning Group of the Institute for Information Technology of the National Research Council of Canada and has been widely distributed for a number of years. ...

A college textbook about CLIPS, Expert Systems: Principles and Programming (ISBN 0-534-95053-1) is available, as well as a book on Jess, Jess in Action: Rule Based Systems in Java (ISBN 1-930110-89-8). CLIPS also contains extensive set of readable documentation.

External links

• Homepage of the project
• What is CLIPS, an explanation
• NASA CLIPS: downloads, information, news, and history
• CLIPS expert system tool: a candidate for the Diagnostic System engine