GnuPlot - Gnuplot is a portable command-line driven interactive data and function plotting utility.
itch.io - An online game marketplace and community.
LabPlot - LabPlot is a KDE-application for interactive graphing and analysis of scientific data.
GOG.com - DRM-free game store, selling both new and old titles. No clients required.
Matplotlib - matplotlib is a python 2D plotting library which produces publication quality figures in a variety...
GeoGebra - GeoGebra is free and multi-platform dynamic mathematics software for learning and teaching.