Not to sidetrack this thread, but why has OpenGL never really seen wide adoption?
Because it kinda sucks compared to DirectX?

It used to have the upper hand, but at DX9 the tables definitely got turned. OpenGL might have extensions a bit faster then DX, but then a developer has to use different vendor-specific extensions to use all the new stuff - and wait a LONG time for the committee to accept it as a standard... with DirectX, you have to wait a bit longer before using the new features, but then it's
one API (the thankfully did away with the caps system).
I remember seeing OpenGL as a driver option when playing duke nukem 3d back in the early 90s.
Original duke3d definitely didn't, you must have either found a 3d-card-vendor specific versions (which I kinda doubt - Quake was the first time that seemed to go mainstream), or have found a dedicated Windows port for it.