[jblow]

They are not OpenGL derivative. I don't know why this rumor propagates. Oh wait yes I do, because those of us who know what the APIs look like in detail generally can't say anything about them because of NDAs. Sigh.

To be clear: None of the APIs you listed are based on OpenGL. PSGL was an OpenGL implementation, but nobody writing a high-performance game used it because it was too slow and unreliable. The APIs used by almost all shipping games you can think of are substantially lower-level.