Benchmarks and timings.
http://www2.staff.fh-vorarlberg.ac.at/~ku/karl/mma.html
A viewer for notebook documents created with Mathematica. Free download. Windows, Unix, MacOS. versions.
http://www.wolfram.com/products/mathreader/
A monthly newsletter devoted solely to Mathematica with links, tips, and articles on various topics. Available in HTML and NB format.
http://omegaconsultinggroup.com/Services/wz.html
Most graphics were generated using Mathematica.
http://darkwing.uoregon.edu/~math/grapict.html
Resources that document various capabilities of Mathematica, such as: articles, books, conference proceedings, courseware, user-submitted MathSource notebooks, and technical notes.
http://library.wolfram.com/
A Mathematica-based package for performing tensor analysis.
http://smc.vnet.net/MathSolutions.html
Comprehensive symbolic and numerical software. Advanced programming language, graphics and sound, programmable interface, notebook documents, and applications library.
http://www.wolfram.com/mathematica/
A spreadsheet frontend to Mathematica.
http://www.smartspread.com/mathematica.php