JEFF (Java Explanation Facility Framework) is an application that can be used with other Java-based (business) rule engines, expert systems and expert system shells in order to provide an explanation of the inference process.
The explanation they provided was supposed to clarify how the ES reached its conclusions or why it asked some question during fact acquisition. Nowadays, traditional ES development environments ("shells") have been replaced by rule engines (RE) and business rule management systems (BRMS), which seem to lack explanation facility functionality. JEFF was created in order to remedy this.
· Java 2 Standard Edition Runtime Environment