Mathematica
Commercial
Wolfram Mathematica (usually termed Mathematica, Mathematica software suite) is a mathematical symbolic computation program.
Qalculate!
Open Source
Qalculate! is a multi-purpose desktop calculator for GNU/Linux (and Mac OS).
GnuPlot
Open Source
gnuplot is a command-line program that can generate two- and three-dimensional plots of functions, data, and data fits.
Matplotlib
Open Source
Matplotlib is a plotting library for the Python programming language and its numerical mathematics extension NumPy.
Compare GraphCalc with alternatives
Compare Mathematica and GraphCalc and decide which is most suitable for you.
Compare Qalculate! and GraphCalc and decide which is most suitable for you.
Compare Matplotlib and GraphCalc and decide which is most suitable for you.