OpenOffice.org: OpenOffice is a free office suite equivalent to Microsoft Office (Word, Powerpoint, Excel, & Acess). It can both read and write the Microsoft file formats (.doc, .ppt, .xls) found on this site. If you do not have the latest version of Microsoft Office, I recommend that you download Open Office.
Some of the animated PowerPoint presentations found on this website will not display properly with Impress (OpenOffice.org's PowerPoint equivalent). To view animated PowerPoint presentations I recommend that you download the free viewer from Microsoft.
Firefox: This cutting edge web browser is my favorite. I tested this site with Firefox.
Thunderbird: This free email software is as good if not better than Outlook or Outlook Express. It is also less prone to viruses.
Gimp: This bitmap based image manipulation program is approximately equivalent to Adobe Photoshop. It is a bit more quirky but the price is right.
Irfanview: I use Irfanview to convert between various image file formats. I'm particularly fond of using it to create .gif files since it allows me to click on the image to pick a transparent color.