The Mac OS X ("Macintosh Operating System Ten") is designed for stability and ease of use. The software features a streamlined, Mac-style Graphic User Interface, built around a sturdy UNIX core called "Darwin." In addition to the user-friendly structure and improved stability of the basic Mac OS X, this "10.2" version (code named "Jaguar") adds a number of additional features, many designed to make it faster and easier to use a variety of multimedia applications and online tools.