rgbPaint
At the beginning of January 2007 Mark Tyler decided to fork version 3.09 of mtPaint to see how easy it would be to create a very basic painting program which could run on the One Laptop Per Child Sugar system.
After just 2 weeks of hacking he managed to finish the program, which functioned well in Sugar, and any other GTK+2 based GNU/Linux system. rgbPaint is much simpler than mtPaint, with no menus for example. Also it is only able to edit and save RGB images. It is a GTK+2 only program, and uses the pixbuf facilities for file handling so it does not depend on file libraries like mtPaint does, i.e. libpng, libjpeg, libtiff, and libungif/giflib.
The rgbPaint sources, and the OLPC activity can be DOWNLOADED HERE.
Here is a screenshot of rgbPaint running in the Sugar environment:
Here is the same binary running on Fedora Core 6:
