OSX

On Thu, 29 May 2003, Jay West wrote: NEXTSTEP was a effectively a NeXT customized CMU Mach microkernel with lots of 4.3BSD mixed in with it. OS X is a revamped version of Mach with FreeBSD (and other more modern BSDs) mixed into it. I'm sure Jordan Hubbard was very instrumental in helping to update the OS to benefit from FreeBSD's code, but OS X is definitely not FreeBSD at its core. It's Mach. I mean, even the name of /kernel/ file is "mach" or rather "/mach_kernel" under OS X. Also, the OS X hostinfo command still reports the Mach version information as was done on NEXTSTEP systems: On my iMac: % hostinfo Mach kernel version: Darwin Kernel Version 6.6: Thu May 1 21:48:54 PDT 2003; root:xnu/xnu-344.34.obj~1/RELEASE_PPC Kernel configured for up to 2 processors. 1 processor is physically available. Processor type: ppc7450 (PowerPC 7450) Processor active: 0 Primary memory available: 256.00 megabytes. Default processor set: 70 tasks, 141 threads, 1 processors Load average: 0.52, Mach factor: 0.60 On my NeXT cube: % hostinfo Mach kernel version: NeXT Mach 3.3: Tue Jul 13 10:33:44 PDT 1999; root(rcbuilder):mk-171.14.obj~22/RC_m68k/RELEASE_M68K Kernel configured for a single processor only. 1 processor is physically available. Processor type: MC680x0 (68040) Processor speed: 25 MHz Processor active: 0 System type: 2 Board revision: 0x0 Primary memory available: 64.00 megabytes. Default processor set: 38 tasks, 66 threads, 1 processors Load average: 0.40, Mach factor: 0.83 The information about OS X being FreeBSD with a pretty Apple GUI on top of it tends to come from some misguided slashdotters who lack historical perspective. That's not to slight FreeBSD's contributions, but they're better considered as "renovation work" to what had already been in place for a decade. -brian.