amiga?

[alx]

Amiga isn't based on mach, but MorphOS has a similar idea (morphos is a kind of AmigaOS clone)

AFAIK MorphOS runs on the "quark" microkernel and has 2 "boxes" - the "Abox", which will run some original Amiga software and the "Qbox" which is still under development and will do new stuff.

I don't know much about morphos, but this page has lots of info.

[Kintaro]

Meh

[ravuya]

mach is a microkernel, and for the referance, anything can run on mach, even linux. and yes osx does run on mach. the cool part of osx, is that its mach, netbsd, and a bit of freebsd./*correct me if im wrong*/ however, i though that  the next amigaos was going to be based on two "box's" running ontop of mach. one was practally the original amigaos for compatibilty and the other one was something new.

I think you're thinking of Rhapsody, the product that eventually matured into OS X... Rhapsody had the "yellow box" (Rhapsody apps), "Blue Box" (classic apps) and so forth, running on top of Mach.