I don't think so. I believe OpenMP qualifies as a (very mature and widely supported) library as well as language extension. Assuming it meets your needs it has

I don't think so. I believe OpenMP qualifies as a (very mature and widely supported) library as well as language extension. Assuming it meets your needs it has (AFAIK) support from all the major compilers (Intel, MS, GCC, LLVM) as well as being able to abstract over GPUs and other sorts of hardware.