Used to describe a series of operating systems developed by Apple, OS X is designed to run only on Mac computers. The operating systems are preloaded onto all models of Mac computers, including the Macbook Pro and Mac Mini. OS X systems tend to be named after big cats, with Tiger, Lion, Leopard, and Snow Leopard being some of the past systems in place. Apple is currently on the ninth major release of an OS X, which sticks to the trend with its nickname Mountain Lion. The operating system has been associated with improvements, such as the ability to synchronize data more efficiently between devices with iCloud and become more social media friendly. This Fall, the newest operating system will be launched, OS X Mavericks. Experts are expecting the system to be even more powerful and efficient than any before.