I have just released version 1.3 of EpochX, a Java based genetic programming framework built specifically for researchers working with genetic programming. Significant additions in version 1.3 include a hooks system which allows the dynamic modification of the population and programs mid-execution and an expanded set of statistics that can be obtained live while the run proceeds. There are a whole swathe of other improvements and bugfixes too.
The documentation for EpochX is also expanding as well. The first half of the Complete Guide documentation has now been published to the website.
Downloads and documentation are all available from www.epochx.org.