Except isn't X86_64 ISA technically property of AMD, not Intel? I know some of the later stuff (SIMD / AVX / SSE / etc) is Intel, but technically I think they

Except isn't X86_64 ISA technically property of AMD, not Intel? I know some of the later stuff (SIMD / AVX / SSE / etc) is Intel, but technically I think they could leave that off and still be successful assuming that would be all that's needed to not be infringing (which I don't know if that's the case or not).