Each tutorial is in one or more of the following four formats:

**cdf**: computable document format

Interactive presentation that can be explored in your browser with the
free CDF Player
plugin. Can also be viewed and modified using Mathematica 8+.

**nb**: Mathematica notebook

These are interactive presentations which can be run in Mathematica 5+.
Also viewable with the CDF
Player plugin, but you won't be able to run them. Try the html
versions instead.

**pdf**: portable document format

Download
Acrobat Reader to view pdfs.

**html**

Can be viewed right here in your browser.