JGAP is a genetic algorithms package written in Java. It is designed to require minimum effort to use out of the box, but is also designed to be highly modular. It allows custom components to be easily plugged in. JGAP version 3.1 is a quality improvement release. It considers multiple user feedback by consolidating the grid functionality, fixing several bugs, introducing a lot of new unit tests, and enhancing the logic of many classes. This release can be downloaded here: http://sourceforge.net/project/showfiles.php?group_id=11618&package_id=48940 For more information visit http://jgap.sourceforge.net Klaus Meffert for the JGAP team