Mach

And so the choices that led to that, right, like the way you described that makes a lot of sense.

And then NeXT and Steve also hired Avi Tevanian for his work at Carnegie Mellon on the Mach kernel, and you're using BSD.

And can you talk a little bit more about those choices and like how it shaped where NeXT was going and why it was...

I mean, I think you've already touched on why it was so revolutionary.