Jess Information

the Java Expert System Shell

Jess is a rule engine and scripting environment written entirely in Sun's Java language by Ernest Friedman-Hill at Sandia National Laboratories in Livermore, CA. Jess was originally inspired by the CLIPS expert system shell, but has grown into a complete, distinct Java-influenced environment of its own. Using Jess, you can build Java applets and applications that have the capacity to "reason" using knowledge you supply in the form of declarative rules. Jess is suprisingly fast, and for some problems is faster than CLIPS itself (using a good JIT compiler, of course.)

The core Jess language is still compatible with CLIPS, in that many Jess scripts are valid CLIPS scripts and vice-versa. 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 adds many features to CLIPS, including the ability to manipulate and directly reason about Java objects. Jess is also a powerful Java scripting environment, from which you can create Java objects and call Java methods without compiling any Java code.

Questions or comments? Contact ejfried@ca.sandia.gov

Last modified: Tue Feb 16 10:09:14 1999