GNU Octave - GNU Octave is a programming language for scientific computing.
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.
QtOctave - QtOctave: a front-end for Octave/un Front-End para Octave
Xcos - Xcos is a graphical editor to design hybrid dynamical systems models.
MATLAB - A high-level language and interactive environment for numerical computation, visualization, and programming
Function Analyzer - see the graph of a function