GeoGebra CAS Calculator - Free online algebra calculator from GeoGebra: solve equations, expand and factor expressions, find derivatives and integrals
GnuPlot - Gnuplot is a portable command-line driven interactive data and function plotting utility.
Geometry Pad - Geometry Pad is a dynamic geometry application for iPad and Android tablets.
GeoGebra - GeoGebra is free and multi-platform dynamic mathematics software for learning and teaching.
Dr. Geo - Dr. Geo, a software to design & manipulate interactive geometric sketches.
SciDaVis - SciDAVis is a free application for Scientific Data Analysis and Visualization.