A free, GPL, non-interactive software package for producing plots, charts, and graphics from data. It was developed in a Unix/C environment and runs on various Unix, Linux, and win32 systems.
Constructs ray diagrams explaining image formation by mirrors and thin lenses.
Learn life science, counting, letter recognition and more.
Build, study and visualize all kinds of crystal structures.
Simulates the sky as it appears today or a thousand years ago.