Xoctave - The Affordable Matlab alternative which makes you save money. Xoctave is a powerful software that is meant to unleash the power of GNU Octave by creating a complete scientific computing environment.
GNU Octave - GNU Octave is a programming language for scientific computing.
MATLAB - A high-level language and interactive environment for numerical computation, visualization, and programming
QtOctave - QtOctave: a front-end for Octave/un Front-End para Octave
Anoc Octave Editor - Write scientific documents in LaTeX and perform mathematical calculations in Octave. Visualize the result in a PDF (LaTeX) or in a plot (Octave)
SMath Studio - Tiny, powerful, free mathematical program with WYSIWYG editor and complete units of measurements support.