[makomk]

I'm not sure how useful one of those would really be, to be honest. There's not really much benefit in terms of openness - even though the architecture is open, these actual implementations are entirely proprietary with license agreements that forbid reverse-engineering. Plus it's just not as widely supported as ARM on the software side right now.

[Tor3]

The 'openess' does nothing for end-users, but it makes a difference for chip vendors - they don't have to pay license fees, unlike for ARM.