JEFF is an explanation facility framework written in Java. Explanation facilities date from the era of expert systems (ES), where they were used in order to provide an explanation about 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 Nowadays, traditional ES development environments ("shells") have been replaced by rule engines (RE) and business rule management systems (BRMS), which seem to lack explanation facility functionality.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.
Zynaptic Reaction is a flexible asynchronous programming framework for Java which may be used to implement complex event-driven applications. It is heavily influenced by the Twisted programming framework developed by TwistedMatrix Labs for the Python programming language. The focus of the Reaction library is on the concurrency and callback model and as such it is application neutral. It can be used to manage lots of concurrent I/O or to farm out compute intensive tasks to multicore processors. As well as being usable as a basic Java library, Reaction can also run as an independent OSGi service and integrate into any GUI framework you choose.