> At the core of OSX is a ton of legacy Unix monolith written in the 70s that I suspect very few in Apple dare ever touch.
The Darwin kernel is regularly updated; for example Apple replaced Unix init and cron with launchd in 2005, achieved full POSIX compliance in 2007, and went to full 64-bit in 2009.
I admit I'm not super familiar with Darwin internals, but on most *NIX systems, init and cron are userspace programs. Does launchd need some special syscalls?
The Darwin kernel is regularly updated; for example Apple replaced Unix init and cron with launchd in 2005, achieved full POSIX compliance in 2007, and went to full 64-bit in 2009.
http://en.wikipedia.org/wiki/Darwin_%28operating_system%29