I think Lion was released as "Mac OS X", and they changed it to "OS X" later. http://www.macrumors.com/2012/02/16/apple-officially-drops-mac-name-from-os-x-mou

I think Lion was released as "Mac OS X", and they changed it to "OS X" later. http://www.macrumors.com/2012/02/16/apple-officially-drops-mac-name-from-os-x-mountain-lion/ http://www.macrumors.com/2012/02/16/apple-officially-drops-m... http://appleinsider.com/articles/12/02/16/with_mountain_lion_apple_officially_drops_mac_from_os_x_name http://appleinsider.com/articles/12/02/16/with_mountain_lion...