Building a demo and building a full kernel are two very, very different things. In addition, it really says nothing about the design, but the implementation (again, we come back to implementation). There's no reason you couldn't implement orthogonal persistence in a Unix-like system, even if it's not optimal.

Honestly, I'm sort of baffled we're still arguing about this. I can't stand Unix-like kernels, I just believe that this particular tutorial is excellent at teaching the basic concepts required to put together any OS. If you find a tutorial of this sort of quality for any other design, submit it and I'll be certain to upvote it.

The world needs more OS designers, and tutorials of this sort lower the barrier to entry.

Edit: Also, if you're on Freenode by any chance, shoot me a PM (my nick is my username here). I always enjoy talking with someone who's as passionate about OS technology as I am.

thank you for that link, very interesting stuff!

Any insight on how this compares to other technologies out there ? Forth ?