I have used Linux for years and also use Mac OSX. OSX doesn't have anyof the licensing B.S. This use to be only at the corporate level in IT shops such as very long license keys that have to be typed in meticulously but now coming to M$h!t Vista.
That's because Apple has propietary hardware! Anytime you buy a new Mac, you get the OS with it. You are not allowed to build your own system. That is the true BS.