It's interesting (although possibly not to yourself, sorry) but Apple is a hardware company and they don't really sell software, or license software. They don't compete against Microsoft, they compete against OEMs like Dell, HP, Acer etc.
Maybe i've got a weird perception of economics market, but i think they're compete, maybe not in a direct way, Microsoft too. Apple are not only an hardware compagny, they product hardware and software. I think they compete OEMs and Microsoft both. But Apple's case is more "complicated" than others, they're on market with differents products.