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.
Executable versions of Octave are provided for certain Linux distributions. For more information, go to the download page for Octave.
Manual is available on the GNU Octave website.