New Patch Fixes 43 Flaws In OS X, Many Serious 2146
Exactly.
Oh, yes, it is. It is much faster than Cygwin could hope to be because of this.
And sometimes the compatibility code does seem to be 'in the codepath' for Mac apps. Apple has many thread libraries, but it appears that they've integrated them all with pthreads in a way that cost performance.
On paper this is bad for security. If, perish the thought, there *are* security vulnerabilties in, say, PThreads "real" Mac apps might be threatened even though they do not use PThreads themselves. This on *top* of any bugs that may be in NSThreads, Mach, and so on.
They are clearly not the same OS from a consumer point of view.
They are also not the same codebase.
I think so. So does X-Open, for that matter: they have their own compatibility tests. But you are also right in saying that if you make the test too strong, you wind up...
It is simply fallacious to say that OS X is secure because it is "Unix". It isn't, and if it were, that would not make it secure.