Microsoft announced the development of Windows in 1983 as a graphical user interface for MS-DOS. Windows has evolved over two families of designs - 3.x and 4.x included Windows 95 which completed the migration to 32-bit code, while the NT family started with NT 3.1 in 1993 and uses a newer kernel. Windows now runs on many processor architectures and has changed from a GUI product to a modern operating system.