"Tuxpaint is an open source graphics program that occupies a special niche: it is designed for children. This makes it a rarity in the software community known for every developer scratching his or her own itch. Thankfully there are developers reaching out of their comfort zone to write applications for those too young to learn Bash and Python on their own — without that effort, kids might not get exposed to free software until they took programming. If you have never looked at it, Tuxpaint deserves some attention, both because it is a great product for kids, and because it may make you rethink the approaches we take to user interfaces. On top of that, there are some intriguing raster graphics functions hidden behind that seemingly simple interface
"You can find Tuxpaint packaged for almost every Linux distribution as part of the main package management system, so installing it should be trivial. Check the version number, though — the latest release is 0.9.21, which hit on May 10, 2010. Binaries are available on the project Web site for several distributions, as well as Windows, Mac OS X, and Nokia's Maemo handheld platform."