At Microsoft's Game Developers Conference (GDC) 2004, the company announced a new software-development platform for gaming called Microsoft XNA. The platform is designed for future versions of Windows, Windows Mobile-based devices, and the Xbox. The unified platform, which is based on Microsoft's DirectX gaming technology, gives game developers a consistent set of tools across Microsoft's platforms. XNA will help bring the features of Xbox Live--including billing, friends, logon, matchmaking, and security--to Windows developers. It will also include a reference design for input devices, such as controllers. How XNA is different from DirectX isn't entirely clear, but XNA is expected to play a big part in the next-generation Xbox, as well as the next version of Windows (code-named Longhorn)