Numerical and Symbolic Calulation

SMath Studio – An absolutely free mathematical program with „paper“-like interface and numerous computing features (with integrated mathematical reference book).

Matlab/GNU Octave – A high-level interpreted language, intended for numerical computations. The Octave language is quite similar to Matlab so that most programs are easily portable.

(wx)Maxima

Scilab – An open source scientific software package for numerical computations providing a powerful open computing environment for engineering and scientific applications.