>>9
Apple did not design Objective C. They maintain it, but it's still a part of GCC and would continue to exist even if Apple dropped development. Further, Objective C was already used in several places before OS X existed.
C was created by one person who was working in the research department of a telephone company, which just so happened to be developing an operating system. Further, C's specific purpose was for portability - exactly going against the reasoning I described in my post, i.e. that .Net only provides pseudo-portability.
Also, you're splitting hairs. Without the OS, Microsoft's software would be irrelevant.
(In any case, this thread is supposed to be about D, so let's try and steer back onto course...)