| Original author(s) | Eric Hakenholz, Rene Grothmann |
|---|---|
| Written in | Java |
| Operating system | Microsoft Windows, Mac OS X |
| Type | Interactive geometry software |
| License | GNU General Public License |
| Website | zirkel.sourceforge.net sourceforge.net/projects/zirkel/ |
C.a.R.– Compass and Ruler (also known as Z.u.L., which stands for the German "Zirkel und Lineal") – is a free and open source interactive geometry software that can do geometrical constructions in Euclidean and non-Euclidean geometry. The software is Java based. The author is R. Grothmann of the Catholic University of Eichstätt, Germany. It is licensed under the terms of the GNU General Public License (GPL).