Honestly, probably NVIDIA itself, since they contribute significantly to many open-source projects (MLIR), and also make their SoTA GEMM/Conv implementations open-source and available for study (Cutlass).
*> also make their SoTA GEMM/Conv implementations open-source and available for study (Cutlass)"
Cutlass is a fine piece of engineering, but it is not quite as good as their closed source libraries in real world workloads. There is secret sauce that is not open sourced.
