GNU Octave, free software Matlab replacement
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.
Visit http://www.gnu.org/software/octave for more information on downloading, installing, using, and getting involved in the GNU Octave project.
Ways to help. We encourage you to create high-level packages in GNU Octave with the goal of creating replacement functions for packages provided by Matlab. You can learn more about getting involved in GNU Octave by joining their mailing list and checking the "help wanted" page.