C.a.R. / Z.u.L.
Cardoid - Example of a Track in C.a.R.
C.a.R. (Compass and Ruler, Z.u.L. "Zirkel und Lineal" in German) is a simulator for geometric constructions with compass and ruler written in Java.
Beyond elementary constructions, macros, tracks, animations, expressions, conic sections, functions and much more are possible. C.a.R. can export constructions to HTML or graphic files in various formats.
The software is is open source under GPL.