It's entirely possible that Apple takes code or inspiration from the Linux software project, but I think it's better to say that OS X is Unix based. Even if Linux and Darwin hail from Unix roots, at some point, I think they become separate projects with separate interests and fates. What's good or bad for one doesn't have to be the same for the other.

When I think of what organizations will be competing on machine-learning backed features like intention prediction or voice search, I think of Apple, Microsoft, or Google. Those OS features won't be inside the OS. They'll be backed by a wealth of proprietary data hidden behind company servers.

I think user expectations for what a modern OS ought do will evolve, and I don't think Canonical or Redhat will be able to catch up to Microsoft, Apple, or Google.

Eventually, what we think of "Linux OS" will be Android (and if you want, OS X) and maybe some other offerings by these big giants, but the most user-demanded features won't be on the OS. Therefore, Samsung can't just fork Android and expect to compete sans Google, and Canonical or Redhat won't be able to compete either.

> It's entirely possible that Apple takes code or inspiration from the Linux software project, but I think it's better to say that OS X is Unix based.

Apple can't take code from Linux as the code is GPL licensed. OSX is largely based on NeXT and BSD. Linux and OSX are both POSIXish though.

OS X had been UNIX certified, at some point, though. Don't know if that is still true

It is. Various optional things from POSIX are missing though (https://github.com/uxcn/yafd/blob/master/src/c/pthread-dw.h).

No, OSX is based on NeXT, which was based on Mach, and BSD. As far as I know, iOS is proprietary.