JESS

Jess, the Java Expert System Shell
New! Jess version 2.2 is now available for download! Version 2.2 is a maintainence release, with a few new features and several bug fixes. Version 2.0 added many new features, including the ability of Jess code to call Java code, and vice-versa. See the first draft of the Jess Manual for more information about Jess features.

Jess is a clone of the core of the CLIPS expert system shell. Jess was written entirely in Sun's Java language by Ernest Friedman-Hill at Sandia National Laboratories is Livermore, CA.

Here Jess is solving "Monkey and Bananas", a classic AI planning exercise. A monkey in a room full of chests, keys, and ladders, along with some hidden fruit, is trying to satisfy her hunger, equipped only with a set of heuristics for manipulating objects. Push a button to find your favorite fruit. The flashing lights correspond to events within the system: rules firing, facts being asserted, etc.

Jess would appear here if you had a Java-aware browser.
Jess is downward compatible with CLIPS, in that every valid Jess script is a valid CLIPS script. Like CLIPS, Jess uses the Rete algorithm to process rules, a very efficient mechanism for solving the difficult many-to-many matching problem (see for example "Rete: A Fast Algorithm for the Many Pattern/ Many Object Pattern Match Problem", Charles L. Forgy, Artificial Intelligence 19(1982), 17-37.)

Jess contains only the essential features of CLIPS, and leaves out a lot, including COOL, the CLIPS Object Oriented Language extension; but it is a powerful, fast, and efficient tool with many applications.

Jess is free and can be downloaded here.
For more info about Jess, contact ejfried@ca.sandia.gov.
You can learn more about CLIPS from Intelligent Software Professionals.

The CLIPS source for the Monkey and Bananas problem.