[namibj]

Except that, for CUDA, they do. https://github.com/NervanaSystems/maxas exhibited significantly higher performance than Nvidia's own SGEMM kernel, and https://github.com/mangpo/swizzle-inventor beats all named competitors in the non-texture-memory-input-using implemention. Namely, NVIDIA Performance Primitives, ArrayFire, and Iandola et al ( https://doi.org/10.1109/ICIP.2013.6738436 ).

As for GC implementations: did you consider ZGC in that statement? It's GPL 2.

[pjmlp]

Yes I did "all sponsored by deep pockets corporations."

Take their money out of the equation and the quality would be as the "state of the art GC" that CPython and MRI Ruby enjoy.

[namibj]

I see. Your sentence structure is a bit confusing and was successful in causing me to parse it as if you were referring to Java, .Net, and JavaScript with pure open source managed runtimes.