Linux is just the kernel. Distributions should certify. And I do not see anyone going fot it. There is at least one distribution posix certified: Inspur K-UX.

Linux is just the kernel. Distributions should certify. And I do not see anyone going fot it. There is at least one distribution posix certified: Inspur K-UX. The equivalence in linux land should be LSB, which many distributions certify to.