OctPlot is free open source software under the terms of the GNU General Public License (GPL). OctPlot is a handle graphics package for Octave, the free alternative to MATLAB(TM). OctPlot provides quality postscript(TM) and screen graphics.
GNU Octave is a high-level language, primarily intended for numerical computations. It provides a convenient command line interface for solving linear and nonlinear problems numerically, and for performing other numerical experiments using a language that is mostly compatible with Matlab. It may also be used as a batch-oriented language.