[jhj]

> Either CUDA will open up, if it is to survive or open API use will spread.

I don't really think so, at least not anytime soon while the hardware functionality continues to evolve so much, and while they seem to be concentrating on the high end devices/architecture rather than low-end stuff.

I've been more or less exclusively writing CUDA for the past decade in the AI/ML space (though have spent some time with OpenCL, Vulkan and other things along the way too). What a GPU is or should be I don't think has reached an evolutionary end yet. CUDA also is not a static thing, and it has co-evolved with the hardware, not being locked into some static industry standard with a boatload of annoying glExtWhatever dangling off of it. Over the past decade or so, Nvidia has introduced new ways that the register file can be used (Kepler shuffles), changed the memory model of GPUs and the warp execution model (to avoid deadlock/starvation by breaking the lockstep behavior somewhat), slowly changing the grid/CTA model (cf. cooperative groups, CTA clusters), adding more asynchronous components to the host APIs and the hardware (async DMAs), and has constantly changed the underlying instruction set, all of which leaks into CUDA in some way.