C.a.R. is dynamic geometry program. Basically, it simulates compass and ruler constructions on a computer.

But on a computer, much more is possible.

C.a.R. works on all modern platforms. Constructions and assignments can be embedded into web pages easily. C.a.R. has been translated in many languages. C.a.R. can be used free of charge, and the source is available under the Gnu General License.