While the discussion in that thread may or may not apply to OS X, be very careful when saying "X is true about Mach therefore X is probably true about Darwin".

While the discussion in that thread may or may not apply to OS X, be very careful when saying "X is true about Mach therefore X is probably true about Darwin". A friend of mine put it very well: OS X was Mach once in the same way that orcs were elves once.