Personal Algebra Tutor - Enter your algebra problems and get instant step-by-step solutions with explanations.
http://www.cyberedinc.com/
Computer algebra system that does arithmetic of arbitrarily long integers and fractions, symbolic calculations, graphics, and other numerical calculations. Free download. Documentation.
http://www.bway.net/~lewis/
written in Fortran77; provides routines for solving systems of simultaneous linear equations, least-squares solutions of linear systems of equations, eigenvalue problems, and singular value problems.
http://netlib2.cs.utk.edu/lapack/
Algebra software resources compiled by The Math Forum.
http://mathforum.org/algebra/alg.software.html
Magazine of the MuPAD Research Group devoted to MuPAD, teaching with MuPAD, and mathematical research.
http://www.mathpad.org/
CREP is designed to deal with categories whose morphism spaces are finite-dimensional over a field k. The main example of a category with this property is the category of finite-dimensional representations of an associative unital k-algebra.
http://www.mathematik.uni-bielefeld.de/~sek/crep.html
A conversion tool by François Thomasset. Written in OCaml, free under GPL.
http://www-rocq.inria.fr/~thomasse/Maple-MuPad/
An experimental free computer algebra system built on top of GiNaC, CLN and a program to interpret C and C++ commands.
http://www.fis.unipr.it/~stefanw/gtybalt.html