Barry Cox

General Mathematics

Wolfram MathWorld - A collection on all things Maths related.
Wolfram Demonstrations Project - A handy resource of demonstrations written in Mathematica. The demos can be accessed by non-Mathematica users through the web previews or the Free Mathematica player. My demonstrations are here .
Project Euler - A series of challenging mathematical/computer programming problems.
The On-Line Encyclopedia of Integer Sequences - If you have an integer sequence and are wondering if it is known before, this searchable encyclopedia is invaluable.

Bloodshed Dev-C++ - Open Source C/C++ IDE for Windows
Julia - A programming language designed for high performance computational problem. Julia is an open source project.
FreeMat - A free environment for rapid engineering and scientific prototyping and data processing. It is similar to MATLAB but is available under the GPL license.
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator developed as Sandia National Labs.
Maple - Symbolic and computational mathematics package.
Mathematica - Symbolic and computational mathematics package.
MATLAB - Mainly computational mathematics package.
MiKTeX - A TeX/LaTeX implementation.
MPICH - Message passing interface for parallel processing.
POV-Ray - Persistence of Vision Raytracing software.
SciLab - Open source software for numerical computation.
TeX Users Group - A membership-based not-for-profit organization for anyone who uses the TeX typesetting system created by Donald Knuth.
VMD - Visual Molecular Dynamics.