SciDaVis - SciDAVis is a free application for Scientific Data Analysis and Visualization.
GnuPlot - Gnuplot is a portable command-line driven interactive data and function plotting utility.
OriginLab - OriginLab is a data analysis tool that provide the engineers and scientist with the technical charts and system for 2D and 3D plotting and all kind of fitting including curve and peak fitting.
GeoGebra CAS Calculator - Free online algebra calculator from GeoGebra: solve equations, expand and factor expressions, find derivatives and integrals
LabPlot - LabPlot is a KDE-application for interactive graphing and analysis of scientific data.
Geometry Pad - Geometry Pad is a dynamic geometry application for iPad and Android tablets.