Jess

Jess is a rule engine for the Java platform, and is a superset of CLIPS programming language, developed by Ernest Friedman-Hill of Sandia National Labs. In at least one (possibly two) of my expert systems classes I actually wrote some programs in the CLIPS language. Jess provides rule-based programming suitable for automating an expert system, and is often referred to as an expert system shell. In recent years, intelligent agent systems have also been developed, which provide a similar capability. Rather than a procedural paradigm, where a single program has a loop that is activated only one time, the declarative paradigm used by Jess continuously applied a collection of rules to a collection of facts by a process called pattern matching. Rules can modify the collection of facts, or they can execute any Java code. Jess can be used to build Java applets as well as full applications that use knowledge in the form of declarative rules to draw conclusions, and inferences.