matplotlib is a python 2D plotting library which produces publication quality figures in a variety of hardcopy formats and interactive environments across platforms. matplotlib can be used in python scripts, the python and ipython shell (ala matlab or mathematica), web application servers, and six graphical user interface toolkits. matplotlib tries to make easy things easy and hard things possible. You can generate plots, histograms, power spectra, bar charts, errorcharts, scatterplots, etc, with just a few lines of code.
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.
FreeMat is a free environment for rapid engineering and scientific prototyping and data processing. It is similar to commercial systems such as MATLAB from Mathworks, and IDL from Research Systems, but is Open Source. FreeMat is available under the GPL license.
The newsgroup 'comp.soft-sys.matlab' is a forum for discussing issues related to the use of Matlab, the scientific calculation and visualization package from MathWorks Inc. This includes discussion of similar software packages like Xmath, Octave, RLab. Appropriate discussion in the group will include both general Matlab issues and platform-specific questions, and discussion comparing Matlab to other systems.
Lush is an object-oriented programming language designed for researchers, experimenters, and engineers interested in large-scale numerical and graphic applications. Lush is designed to be used in situations where one would want to combine the flexibility