provide improved audio in computer games. These cards provide improved 3D audio and provide audio enhancement that is generally not available with integrated alternatives, at the cost of marginally lower overall performance. The Creative Labs SoundBlaster line was for many years the de facto standard for sound cards, although its popularity dwindled as PC audio became a commodity on modern motherboards. Physics processing units (PPUs), such as the Nvidia PhysX (formerly AGEIA PhysX) card, are also available to accelerate physics simulations in modern computer games. PPUs allow the computer to process more complex interactions among objects than is achievable using only the CPU, potentially allowing players a much greater degree of control over the world in games designed to use the card. Virtually all personal computers use a keyboard and mouse for user input, but there are exceptions. During the 1990s, before the keyboard and mouse combination had become the method of choice for PC gaming input peripherals, there were other types of peripherals such as the Mad Catz Panther XL, the First-Person Gaming Assassin 3D, and the Mad Catz Panther, which combined a trackball for looking / aiming, and a joystick for movement. Other common gaming peripherals are a headset for faster communication in online games, joysticks for flight simulators, steering wheels for driving games and gamepads for console-style games. Software Computer games also rely on third-party software such as an operating system (OS), device drivers, libraries and more to run. Today, the vast majority of computer games are designed to run on the Microsoft Windows family of operating systems. Whereas earlier games written for DOS would include code to communicate directly with hardware, today application programming interfaces (APIs) provide an interface between the game and the OS, simplifying game design. Microsoft's DirectX is an API that is widely used by today's computer games to communicate with sound and graphics hardware. OpenGL is a cross-platform API for graphics rendering that is also used. The version of the graphics card's driver installed can often affect game performance and gameplay. In late 2013, AMD announced Mantle, a low-level API for certain models of AMD graphics cards, allowing for greater performance compared to software-level APIs such as DirectX, as well as simplifying porting to and from the PlayStation 4 and Xbox One consoles, which are both built upon AMD hardware. It is not unusual for a game company to use a third-party