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DPlot - DPlot graphing software lets scientists and engineers graph, plot, analyze, and manipulate data.
GnuPlot - Gnuplot is a portable command-line driven interactive data and function plotting utility.
Portable Python - Minimum bare bones portable python distribution with PyScripter as development environment.
Dr. Geo - Dr. Geo, a software to design & manipulate interactive geometric sketches.
WinPython - The easiest way to run Python, Spyder with SciPy and friends out of the box on any Windows PC...