These tutorials use java and javascript extensively, so a modern browser is necessary.
KnowItAll may be downloaded for free for academic uses. This software includes many features, including structure drawing.
ISIS/Draw
may be downloaded for free for academic uses. This structure
drawing software, which is available for both Windows and Mac, may be
used with most word processing programs.
Chemscape Chime may be downloaded for free. This plug-in is used for viewing spectra embedded in web pages in the first version of the Spectral Zoo.
