GeoGebra is dynamic mathematics software for schools that joins geometry, algebra, statistics and calculus through graphing and spreadsheets. GeoGebra can be downloaded for free (from www.geogebra.org/download) to work on the "desktop."On the one hand, GeoGebra is an interactive geometry system. You can do constructions with points, vectors, segments, lines, polygons and conic sections as well as functions while changing them dynamically afterwards. On the other hand, equations and coordinates can be entered directly. Thus, GeoGebra has the ability to deal with variables for numbers, vectors and points. It finds derivatives and integrals of functions and offers commands like Root or Vertex.