Development
When development started in 1988, Windows NT was to be known as OS/2 3.0, the third version of the operating system developed jointly by Microsoft and IBM. In addition to working on three versions of OS/2, Microsoft continued parallel development of the DOS-based and less resource-demanding Windows environment. When Windows 3.0 was released in May 1990, it was so successful that Microsoft decided to change the primary application programming interface for the still-unreleased NT OS/2 (as it was then known) from an extended OS/2 API to an extended Windows API. This decision caused tension between Microsoft and IBM, and the collaboration ultimately fell apart. IBM continued OS/2 development alone, while Microsoft continued work on the newly-renamed Windows NT. Windows NT would be far more successful than OS/2, due largely to Microsoft's market prowess.
Microsoft hired a group of developers from Digital Equipment Corporation led by Dave Cutler to build Windows NT, and many elements reflect earlier DEC experience with VMS and RSX-11. The OS is designed to run on multiple instruction set architectures, with the kernel separated from the hardware by a hardware abstraction layer. APIs are implemented as subsystems atop the publicly undocumented Native API; it was this that allowed the late adoption of the Windows API. Originally a microkernel design, subsequent releases have integrated more functions into the kernel for better performance. Windows NT was the first operating system to use Unicode internally.
[edit]
Releases
Version Editions Released Build Number
Windows NT 3.1 Workstation, Advanced Server 1993 July 528
Windows NT 3.5 Workstation, Server 1994 September 807
Windows NT 3.51 Workstation, Server 1995 May 1057
Windows NT 4.0 Workstation, Server, Server Enterprise Edition, Terminal Server, Embedded 1996 July 1381
Windows 2000 (NT 5.0) Professional, Server, Advanced Server, Datacenter Server 1999 December 2195
Windows XP (NT 5.1) Home, Professional, Media Center, Tablet PC, Starter, Embedded, 64-Bit, Reduced Media 2001 August 2600
Windows Server 2003 (NT 5.2) Standard, Enterprise, Datacenter, Web 2003 March 3790
The first release was given version number 3.1 to match the contemporary 16-bit Windows; magazines of that era claimed the number was also used to make that version seem more reliable than a ".0" release. Windows NT 3.1 ran on Intel IA-32, DEC Alpha, MIPS R4000, and PowerPC processors; Intergraph Corporation ported Windows NT to its Clipper architecture and later SPARC, but neither version was sold to the public. Windows NT 4.0 was the last major release to support Alpha, MIPS, or PowerPC, though development of Windows 2000 for Alpha continued until 1999, when Compaq stopped support for Windows NT on that architecture. Only 2 of the Windows NT 4.0 variants (IA-32 and Alpha) have a full set of service packs available. All of the other ports done by 3rd parties (Motorola, Intergraph, etc.) have few, if any, publically available updates.
Windows XP 64-Bit, Windows Server 2003 Enterprise, and Windows Server 2003 Datacenter support Intel's IA-64 processors. As of March 30, 2005, Microsoft had released to manufacturing three editions for the AMD64: Windows XP Professional x64, Windows Server 2003 Standard x64, and Windows Server 2003 Enterprise x64.
[edit]
"NT" designation
It is popularly believed that Dave Cutler intended the initialism "WNT" as a pun on VMS, incrementing each letter by one; while this would have suited Cutler's sense of humor, the project's earlier name of NT OS/2 belies this theory. Another of the original OS/2 3.0 developers, Mark Lucovsky, states that the name was taken from the Intel i860 processor—code-named "N-Ten"—which served as the original target hardware. Various Microsoft publications, including a 1998 question-and-answer session [1] (http://www.microsoft.com/billgates/columns/1998q&a/QA5-6.asp) with Bill Gates, reveal that the letters were expanded to "New Technology" for marketing purposes but no longer carry any specific meaning.
The letters were dropped from the name of Windows 2000. This action ostensibly reflected Microsoft's intent to unify its home and business lines, then represented by Windows 98 and Windows NT 4.0, but this goal would not be achieved until the introduction of Windows XP. Some believe this to be the result of a trademark dispute between Microsoft and Nortel.
