On Wed, Dec 31, 2014 at 12:42 PM, Diomidis Spinellis <dds@aueb.gr> wrote:
Thank you for stressing the importance of Solaris as a Unix descendant for which source code is available. 
​Amen​.   BTW:  
I really don't consider Solaris a pure System V ​either.  Larry and his siblings hacked on it pretty heavily.    SGI's Iris and NCR's RAS were much closer to "pure" Summit code and that was not "Research" UNIX.   They all devolved.

It's a pity that we don't have public source code for the Solaris versions 2.1 to 10, so there's a 15 year gap between System V R4 and the first release of Open Solaris.

I don't agree that BSD systems are a clone of Unix. 
​Ditto.   To me, anything post First Edition of Research UNIX is UNIX. Where hacking started and was slowly changed.   But the core BTL DNA was is left intact.    Idris, Linux, Minux, etc. were clones, where the API was followed and the DNS regenerated.

​Either way, it really does not matter too much.