GeoGebra

GeoGebra is a free interactive mathematical software for education in colleges and universities. Its creator Markus Hohenwarter, the project began in 2001 at the University of Salzburg and continues in the Atlantic University, Florida.

GeoGebra is written in Java and therefore available on multiple platforms.
It is basically a "geometric processor"and a "processor algebraic", ie a collection of mathematical software that brings interactive geometry, algebra and calculus, and therefore can be used also in physics, business projections, estimates and strategic decision other disciplines.

His closest category is "dynamic geometry software" [English: DAS].

GeoGebra constructions can be made from points, lines, rays, segments, vectors, tapered ... etc. - by direct use of tools operated with the mouse or the entry of commands into the input bar with the keypad or by selecting from the list available -. All layout is modifiable in a dynamic way: ie if an object B depends on another A.

GeoGebra allows dynamic tracing geometric constructions of all kinds as well as graphing, algebraic treatment and calculation of real functions of real variable, their derivatives, integrals, etc.