GeoGebra, GnuPlot, WinPython, Grapher, SciDaVis, Golden Software Grapher, MagicPlot, Pygal, DPlot, Aveloy Graph, Graphmatica, pro Fit, Matplotlib, Portable Python, Magma, Lybniz, Mathmatiz, Autograph, Enthought, ScicosLab, GeoGebra CAS Calculator, Core Plot, Reinteract, MagicPlot Viewer, Mathomatic are some alternatives to Python(x,y).