For machines that already have Mac OS X Lion, skip to slide 3. Snow Leopard First First of all, Mountain Lion is only available through Apple's Mac App Store. And, Apple's Mac App Store can only ...

Since Mac OS X 10.5 Leopard was released in 2007 ... In 2009, that meant Leopard was followed by Snow Leopard; in 2012, Mountain Lion followed Lion. It’s been a while, and Apple has moved from big ...