[slavik81]

Disclaimer: I work on AMD ROCm, but my opinions are my own.

There's also HIP[1], which can be used as a thin wrapper around CUDA, or with the ROCm backend on AMD platforms. It doesn't yet match CUDA in either breadth of features or maturity, but it's getting closer every day.

[1]: https://github.com/ROCm-Developer-Tools/HIP

[gnufx]

As I understand it, that has to work for the CORAL 2 US "exascale", so people who've been proved fairly right so far obviously have some confidence in it. (de Supinksi of Livermore said he'd be out of a job if conventional wisdom was right, though it was pretty obvious at the time that it wasn't.) Free software too, praise be.

[TinkersW]

It looks good but without Intel iGPU support I don't think any gamedevs would use it :/

I wish all the GPU companies would get together and make a standard based on C++ and stick with it.