Exophase
Nothing good will ever come of Exophase.
What that means is that whoever makes GPU drivers are allowed to add new functions to OpenGL (ES or whatever) that aren't a part of the core standard, but are still officially documented. They're called extensions and the code can check for and register them. Some extensions are common and used by lots of different companies, others are specific to one vendor or even one GPU. http://www.opengl.org/documentation/extensions/...the "exposed via extensions" part