Well I’m working on one with the help of some friends/colleagues but it’s still very simple, it has only basic widgets for now: buttons, check boxes, edit boxes, sliders/progress bars and windows of course. Both keyboard and mouse interaction is possible.
The project is not meant to ever be a full-featured GUI (there are some references to an OpenGL Swing implementation in some of the other threads if you need complex interfaces) but is more meant for in-game GUIs: simple and skinnable.
I’ll see if I can get a website up and running with some screenshots, a download and the JavaDocs if there’s any interest. (BTW The code is released under the Lesser GPL).