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.

Changes

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.

URL: Jess, the Rule Engine for the Java Platform