I'm the archivist for the free Graphics Gems code base on the web. I do it for free, because this code is so valuable. Others think so, too: there is an average of 100 hits a day on the site. Go look at the online list of what's in this volume to see if it's for you.
Highlights (for me) include point in polygon testing (yeah, I wrote it), the arcball, matrix decomposition, an implicit surface polygonizer, a fast alternate Phong lighting model, and fast embossing.
The Mac version simply has a different disk in it - better is to get the latest code online.