Hell, Quake itself was written on miniGL which was a subset of an abstraction layer built (IIRC) on top of Glide.
And really, OpenGL at the time was simple too. [Check this OpenGL 1.1 reference](http://www.talisman.org/opengl-1.1/Reference.html) which also includes GLU and GLX function and even with those, the number of calls is very small.
For Direct3D games you must use a 32bit color mode otherwise Windows 8.x/10 will force software rendering which is very slow. Even better, use dgVoodoo2 which is a reimplementation of DirectX 1 to 7 (with a some bits of 8) in Direct3D 11 and provides much better compatibility (also gets rid of the Direct3D 7 2048 surface width limitation, making it possible to play games at 2560x1440 and up).
For Glide, dgVoodoo2 is also very good and you can "cheat" the game to force higher resolutions than what the game thinks it is running at.
I have a lot of old games and everything that isn't DRM encumbered works fine in Windows 10 using dgVoodoo2 and/or some game-specific hacks (Tomb Raider 1 for example is normally a DOS game that you can play using a Glide-enabled build of DOSBox but there was also a Windows version made that used an ancient proprietary 3D API by ATI - someone reimplemented that API and placed extra hacks in there for high resolutions and widescreen support).
I have "I WANT! I WANT! I WANT!" signs blinking in my head as i type this :-P.
(facepalm mainly because i wanted it, i do not know the economical details)
Funny enough, the Forsyth's (and another one from another team member i do not remember now) article sold me more on Larrabee than any PR speak Intel made.
[1] http://tomforsyth1000.github.io/blog.wiki.html#%5B%5BWhy%20d...