Jess

Website: www.jessrules.com

Jess is a rule engine for the Java platform that was developed by Ernest Friedman-Hill of Sandia National Labs.

It is a superset of the CLIPS programming language.

It was first written in late 1995.

The language provides rule-based programming for the automation of an expert system, and is frequently termed as an expert system shell.

In recent years, intelligent agent systems have also developed, which depend on 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 applies 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.

It uses the Rete algorithm to execute rules.