Microsoft Sees Linux As Bigger Competitor Than Apple

Facetious writes "It seems Microsoft doesn't believe the data from Net Applications regarding Linux any more than Slashdot readers do. In a recent presentation, Microsoft CEO Steve Ballmer showed a slide showing, from Microsoft's internal analysis, that Linux client use is clearly ahead of Apple's."

Comments

Re:Apple OS != Linux?

[dadragon]

Do you know whether it's POSIX-compliant?
Yes.

Is it proper to refer to it as a "Unix" or is it a "Unix clone" or "Unix-like system" like Linux?
OS X is a certified UNIX.

I'd also be interested in anything explaining why they went with a Mach microkernel and whether that has any non-negligible impact on performance (i.e. message-passing overhead, switching from kernel to userspace, etc). I'd appreciate anything you are able to explain since I'm honestly rather ignorant about OSX.

The message passing overhead is fairly high compared to other systems like Linux or other BSDs. Unlike monolithic kernels, the Mach based one that Darwin (The UNIX part of OS X) uses actually has to do a full context switch when one makes a system call. That can be slow, especially with TLB flushes and such.

Wikipedia and Apple have some pretty good docs on how it works.