--- USAGE:

I agree we should let people in future write:

if not platform.system('Windows'):

rather than:

if not (platform.system() in ('Microsoft', 'Windows')):

now that our people can no longer rely on Python in Vista correctly 
understanding the plain human intent of such code fragments as:

if platform.system() != 'Windows':

--- DRAFT SPEC:

platform.system(name = None) returns the system name if name is None, 
else returns the system name if name is a well-known alias of the 
system name, else returns None.

The string 'Mac OS X' is a well-known alias for the system 'Darwin'.

The string 'Windows' is a well-known alias for the system 'Microsoft' 
in 2.5.1 Python on Vista.

The system name is itself a well-known alias of the system name. For 
example, 'Darwin' is a well-known alias of the 'Darwin' system that is 
sold as the kernel of 'Mac OS X'.

Etc.