GnuPlot - Gnuplot is a portable command-line driven interactive data and function plotting utility.
Line Graph Maker - Create a line graph for free with easy to use tools and download the line graph as jpg or png file.
GeoGebra CAS Calculator - Free online algebra calculator from GeoGebra: solve equations, expand and factor expressions, find derivatives and integrals
Desmos - A beautiful, innovative, and modern online graphing calculator.
GNU Octave - GNU Octave is a programming language for scientific computing.
GeoGebra - GeoGebra is free and multi-platform dynamic mathematics software for learning and teaching.