Windows 2000 (also known as Win2K, W2K, Win2000 or Windows 2K) is an operating system that was designed to work with computers that have either single or multiple processors. It was designed for 32-bit Intel x86 computers. It is part of the Microsoft Windows NT line of operating systems and was released to manufacturing on December 15, 1999 and officially on February 17, 2000. Windows 2000 comes in four versions: Professional, Server, Advanced Server, and Datacenter Server. Additionally, Microsoft offers Windows 2000 Advanced Server - Limited Edition and Datacenter Server - Limited Edition, which were released in 2001 and runs on 64-bit Intel Itanium processors. Windows 2000 was designed for businesses, but it was also popular with home users. A Home Edition of Windows 2000, codenamed Neptune, was planned, but was never released.