Graph
Plot mathematical functions.
Educational
Speedcrunch
Fast, high precision and powerful desktop calculator.
Tux Paint
Tux Paint is a free drawing program designed for children that's fun and easy to use.
Gcompris
Educational software suite comprising of numerous activites for children 2 to 10.
Tux Typing 2
Educational typing tutor for kids and adults alike.
TuxMath
"Tux, of Math Command" is an educational typing tutor for children.
Marble
Virtual Desktop globe and geographical atlas ; offers viewing of OpenStreetMaps.
Celestia
Space simulation to explore the universe in any direction.
Stellarium
Use your computer as a virtual planetarium.
Maxima
A sophisticated computer algebra system.