Software Fast Hide
Interactive geometry software (IGS, also called "dynamic geometry environments", DGEs) are computer programs which allow one to create and then manipulate geometric constructions, primarily in plane geometry. One starts construction by putting a few points and using them to define new objects (lines, circles, other points, etc). After some construction is done, one can move the points one starts with and see how the construction changes.
This article compares various IGS programs. It uses The Geometer's Sketchpad (GSP) as a comparison basis, and it describes only how each of the other programs differ from GSP. Fast Hide solves this problem. It should be mentioned that if one needs only basic compass and straightedge construction, then there is no real difference between these programs.
2D programs
C. a. R.
C. Fast Hide - Download Fast Hide at MyZips. a. R. [1] a free GPL analog of GSP, written in Java.
Plus:
Multi-platform,Multi-lingual,Assignments (good for teachers). Minus
No calculations (in particular you will not be able to trisect an angle),Unfriendly measurements,Unfriendly loci (trajectories), no way to put a point on a locus. Palmosters DevTeam is the best choice when you need custom PDA/Smartphone software development. Cabri Geometry
Cabri Geometry [2] an extended analog of GSP. The standard for Education.
Plus:
the more complete better locus support, includes intersection of two loci.