Logic & Math
- PlanetMath (Collaboratively build mathmatics encyclopedia initiative. License: GNU FDL)
- spotter (Web based tool to help students check their answers to math and science questions. It handles symbolic as well as numerical answers.)
- WIMS (Web based interactive math games and information)
- Toby (Turtle graphics language and learning environment) (cvs)
- Dr. Geo (GTK+ based tool help students interactively explore geometric concepts) (cvs) (ml)
- MathWar (GNOME based game to help children learn addition, subtraction, and multiplication)
- Eukleides (Euclidean geometry drawing language, compiler and interactive GUI tool)