The Grumpy Editor's GNOME 3 experience

I think using "3D" to describe this is a bit ingenious, as it doesn't at all describe what e.g. gnome-shell does. Its nothing like Quake 3.

However, what gnome-shell does is use the graphics card hardware in the way that modern graphics accelerators really work, not like the previous generation of graphics hardware worked.

Current graphics cards have none of the traditional bitblit or drawing primitives in hardware, and the "native" way to program them is with an API like OpenGL or Direct3D. That doesn't mean you can only program a 3D game using them, it just means that is how you program them.