If there's any confusion, that's absolutely what I plan on doing - but I firmly believe that if it's kept simple/lightweight that it's more than doable. The GUI portions slightly worry me, but they're not happening until much later down the line
> Same with OS X
OS X is BSD with a fresh coat of paint. It really depends if you want to consider the whole experience (which I consider less stellar than most people would care to admit) or the internals (which are the same old unix stuff).
Mach and IOKit and and a gazillion other things are hardly "the same old Unix stuff", if you're talking about the kernel. If you're talking about everything above that level, read Amit Singh's book if you really think there are just splashes of superficial changes at and above the POSIX layer. If you have and you still feel this way, I don't know what to tell you. I'm not saying it's all great, but there's a LOT there.
I see the benefit of documenting each step. The result will be a pretty great tutorial, or at least a very interesting series of blog posts. But what is closed about the development of the current distros?
I hope that Ian is hoping to build a very different kind of distro, breaking the mold. NEXTSTEP was fundamentally a Unix, but everything about it was synthesized to create a totally new organism. Same with OS X. This kind of experimentation hasn't been attempted very much with Linux distros, which mostly amount to different installers and package managers. Etoile comes to mind, and apparently CoreOS is discarding much of the mold, but a completely new, holistically built system would be quite interesting to see. I suspect it hasn't been attempted much because the sheer amount of work is overwhelming. Writing a new shell is a lot of work. Writing a different init, shell, filesystem layout, and window manager, all unified around some new concepts, would be a lot of work. If that's what he's aiming to do, the result will be really interesting to use and learn from.