While studying OpenGL 2, which is gaining widespread availability in mobile devices, I released there were few free/open (as in: anybody can share and contribute) resources on the subject – and too many outdated documentation on legacy OpenGL 1.x.
So a few fellow contributors and I set up a new set of tutorials based on modern OpenGL, through the excellent Wikibooks project (CC-BY-SA).
http://en.wikibooks.org/wiki/OpenGL_Programming
The code samples are in the public domain.
I bet quite a few LDers have something to say on the subject – we would much welcome proof-reading and comments