FreeMat is a free numerical interpreted matrix-oriented computing environment and programming language for rapid engineering and scientific prototyping and data processing similar to MATLAB from Mathworks and GNU Octave. In addition to supporting many MATLAB functions and some IDL functionality, it features codeless interface to external C, C++, and Fortran code, further Freemat provides visualization, image manipulation, and plotting as well as parallel programming (parallel distributed algorithm development via MPI), and some extended volume and 3D visualization capabilities. Some features;

FreeMat is available under the GNU GPL license. For more information (...and download) click here.