Open Source C Education Software

Tux Paint is a free, award-winning drawing program originally created for children ages 3 to 12, but enjoyed by all! It combines an easy-to-use interface, fun sound effects, and an encouraging cartoon mascot who guides children as they use the program. You're presented with a blank canvas and a variety of drawing tools to help them be creative. Along with paintbrush, shapes and text, Tux Paint includes a "stamp" feature to add pre-drawn or photographic imagery to pictures, and a set of "magic tools" that provide filter effects (like blur, tint and waves) and interesting drawing tools (like train tracks, bubbles and grass). Tux Paint includes a collection of "starter" images, both coloring-book style and photo-realistic, and a large collections of stamps are available as a separate download. Additional content can be added by parents & teachers, or downloaded from 3rd parties. Tux Paint is available for Windows, macOS, Android, Linux, & Haiku operating systems, among others.

Stellarium renders 3D photo-realistic skies in real time with OpenGL. It displays stars, constellations, planets, nebulae and others things like ground, landscape, atmosphere, etc.