From the way I understood it, Quartz is it's own screen rendering system based on Display PostScript. In order to "accelerate it using OpenGL" is, from my understanding, impossible, no?
You wouldn't have to stitch OpenGL calls into Quartz... you would sort of have to completely toss Quartz out the window and rebuild the screen rendering engine using OpenGL.
I think a good case in point is a freeware Terminal replacement called <a href="http://www.pollet.net/GLterm/
" target="_blank">GLTerm</a>. It is a terminal replacement that uses OpenGL for rendering, and as such, can't take advantage of all the features given to windows that use Quartz.
At any rate, I'm sure Apple had good reasons for choosing Display PostScript over OpenGL, but I really don't think it is possible to accelerate Quartz by attempting to make it an OpenGL/Display PostScript hybrid