GeoGebra

GeoGebra is an interactive geometry software for education in schools. Most parts of GeoGebra are free software. GeoGebra is written in Java and thus available for multiple platforms.

Its creator, Markus Hohenwarter, started the project in 2001 at the University of Salzburg, continuing it at Florida Atlantic University (2006–2008), Florida State Universit (2008–2009), and now at the University of Linz together with the help of open-source developers and translators all over the world.

Dynamic Geometry, Algebra and Calculus:

GeoGebra is dynamic geometry software. Constructions can be made with points, vectors, segments, lines, polygons, conic sections, and functions. All of them can be changed dynamically afterwards.