Apple makes OSX. OSX is broken down into different versions named after big cats. Tiger, Leopard and Lion are each versions with Lion being the latest. Also like cars, each OS has its own benefits and faults. OSX is usually user friendly. The computers themselves are very sleek and offer a polished look. Apple computers are divided by the software (OSX) and the hardware (Macintosh) and have a market share of a little over 7%. Typically, OSX only works on Mac hardware. Over the last few years a "hackintosh" community has grown that enables users to install OSX on certain non Apple devices, but I'll talk about that later. The downsides are that it is far more expensive than other computers and doesn't offer much game support.