Predefined Versions for Apple Operating Systems

[Walter Bright]

Lots of good points, Jonathan.

The current situation for C #defines for operating systems is an utter disaster. 
I can find zero official guidance from Apple on what to use.

People have remarked that I was denigrating Linux by using lowercase "linux" as 
the version, but nothing of the sort was my intention. It was simply that 
"linux" was the most commonly used predefine in the Linux world.

Maybe we should simply go with "Apple" as the umbrella for the various Apple 
operating systems, and be done with it. Maybe we can set a positive trend there! 
Wouldn't that be nice!