If you want to learn OpenGL, you should get the Red Book (OpenGL Programming Guide). However, all examples in that book are written (or rather printed) in C. For Cocoa lovers, there is some serious translation to do.

There are places on the web that explain OpenGL on OsX, or that have Cocoa examples. Just think of http://nehe.gamedev.net/ where you find some excellent tutorials. Or http://zerobyzero.ca/%7Ektatters/index.html.

But nowhere I found the Red Book told in Cocoa. So I did the examples by myself. I still have to clean everything up (after every 'execrcise', I have a tendency to start experimenting - add lights, walk the camera around etc.…, so I end up with an application that has nothing to do anymore with the original). But once that is done, I'll place the working examples on line. The Icosahederon - to start with - should not be to far away…

Check back later.