FreeMat is an environment for rapid engineering and scientific processing.
It is similar to commercial systems such as MATLAB from Mathworks and IDL
from Research Systems, but is Open Source.

FreeMat includes several novel features such as a codeless interface to
external C/C++/FORTRAN code, parallel/distributed algorithm development
(via MPI), and plotting and visualization capabilities.

WWW: http://freemat.sourceforge.net/