Projects / Jess


Jess is a fast, light rule engine and scripting environment written entirely in Java. You can build Java software that has the capacity to "reason" using knowledge you supply in the form of declarative rules. It is supplied as a programmer's library, making it ideal for embedding in larger applications. Jess includes development tools built on the Eclipse platform. It is free for academic use and can be licensed for commercial use.

Operating Systems

Recent releases

  •  11 Nov 2008 18:27

    Release Notes: This release enhances the QueryResult class, and fixes bugs in slot-specific, no-loop, and salience evaluation in peered engines.

    •  06 Aug 2008 20:20

      Release Notes: This version includes a patch for some issues with default values in inherited templates, and a workaround for folks who need to include the period character in template slot names (see the release notes section entitled "Porting from Jess 7" for details.)

      •  08 Jul 2008 17:19

        Release Notes: This release contains many enhancements to rule engine performance and rule language usability. The semantics of "Java patterns" are greatly improved, and the rule compiler is far more aggressive about optimization.

        •  23 Jun 2008 17:29

          Release Notes: This release adds a number of small convenience features and fixes all outstanding bugs.

          •  02 Apr 2008 14:51

            Release Notes: Support for Eclipse linked projects was added, along with a number of engine bugfixes.


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