Here is a partial list of computing resources I work with regularly and some links I have found very useful.

Maxima

Maxima is a free, open source computer algebra system (CAS) with an impressive range of capabilities and a large user community. The software has a long and interesting history which begins in the 1960s at MIT. My maxima page has some workbooks and information on using this software.

MATLAB/OCTAVE

I use MATLAB for numerical computation and its GNU GPL counterpart Octave for a lot of my numerical work. I will be adding some of my MATLAB/Octave scripts shortly.

LaTeX

These are notes I wrote for a talk I gave on using LaTeX. Here are sample files from the talk:

I use inkscape for all publication quality graphics. This wonderful, versatile program easily renders vector graphics and has numerous useful tools for producing mathematical diagrams.