SAGE
www.sagemath.org
MAGMA
magma.maths.usyd.edu.au/calc/
Discovering Mathematics with Magma
MATLAB
General Matlab Resources on the Web
Matlab Tutorial by Mark Gockenbach
Matlab at the University of Indiana
Matlab introduction from the University of Utah
Matlab at MIT
Matlab at Northwestern University
The MathWorks
Symbolic Math toolbox
Experiments with MATLAB
Numerical Computing with MATLAB
Solving ODE with MATLAB
MAPLE
MATHEMATICA
www.wolfram.com/mathematica/
GAP
www.gap-system.org
PARI/GP
Pari/GP
Octave
GNU Octave is a high-level language, primarily intended for numerical computations. It is freely redistributable software.
R