Again ignoring and misdirection when your point was shown false.
OS X (as a client) has a completely open source base with proprietary software on top. OS X Server has the same, but the tools and utilities that ship with it, and what comprise most the fact that it is the Server version, are open source.
Apple bet the farm on these technologies, and it has paid off.
OSX isn't an open O/S, obviously. You should actually read the news some.
http://www.linuxpipeline.com/showArticle.jhtml?articleId=180206198