I do not. And I use NVidia hardware regularly for GPGPU. But I hate fanboyism.
> NVIDA open-source their CUDA implementation to the LLVM project 5 years ago
Correction: Google developped an internal CUDA implementation for their own need based on LLVM that Nvidia barely supported it for their own need afterwards.
Nothing is "stable" nor "branded" in this work.... Consequently, 99% of public Open Source CUDA-using software still compile ONLY with the CUDA proprietary toolchain ONLY on NVidia hardware. And this is not going to change anything soon.
> one from PGI, that compile CUDA to multi-threaded x86-64 code using OpenMP.
The PGI compiler is proprietary and now property of NVidia. It was previously properitary and independant but mainly used for its GPGPU capability through OpenACC. OpenACC backend targets directly the nvidiaptx (proprietary) format. Nothing related with CUDA.
> Intel being the main vendor pushing for a parallel STL in the C++ standard
That's wrong again.
Most of the work done for the parallel STL and by the C++ committee originate from work from HPX and the STELLAR Group (http://stellar-group.org/libraries/hpx/).
They are pretty smart people and deserve at least respect and parent-ship for what they have done.
More information from Hermut Kaiser (Very Nice Guy btw) here (https://www.youtube.com/watch?v=6Z3_qaFYF84).
They have been the precursor of the idea of parallel "algorithms" in the STL and the concept of "Execution policy" you have in C++17 comes from them.
To the defense of Intel (and up to my knowledge) they have provided the first OSS implementation for compilers for it.