JSAP started out as a one-person project, but has since grown thanks to code and idea contributions from its users. I hope the following is a complete list. Please let me know if I'm leaving anyone out.
EnumeratedStringParser classes, plus a few bug
Suggested the ability to override the use of the ID in automatically-generated usage information.
Pointed out a few bugs in the Ant task and provided solutions (the best kind of bug report there is!)
Provided the vast majority of bug fixes, new features, and associated documentation bringing JSAP to version 2.0! See the v2.0 changelog.