Errr... OSX and iOS are also MACH based. I'd call them 'usable' ? :-) Funny bit is, back in the 90's when Apple bough NeXT, they trashed the NeXT version of MA

Errr... OSX and iOS are also MACH based. I'd call them 'usable' ? :-) Funny bit is, back in the 90's when Apple bough NeXT, they trashed the NeXT version of MACH and used the one that was in... mklinux instead! I bet very few people remember that bit. I remember because I had written the framebuffer console driver for mklinux back then, and seeing my init message when booting the earlier version of OSX (<=10.1 ish, perhaps a bit later too) So I had the privilege of printing kernel crash logs and panics on zillions of devices! I'm so proud! :-)