Windows NT has hit an important milestone. Its launch is now closer to the first Moon landing than it is to today.
With its debut in July 1993, Windows NT ushered in a gloriously pure 32-bit future, free of the 16-bit shackles of the past. While the majority of PCs at the time were running MS-DOS, often with Microsoft's Windows 3.1 perched precariously atop, like a giant lemon balanced on a peanut, the kernel-based NT represented a stab at something entirely new.
Originally intended as a successor for IBM's OS/2, before the collaboration between the two companies foundered on the rocks of the success of Microsoft's Windows, NT required some tasty hardware. Nothing less than a 386-class processor (for the Intel iteration) would do, and running it in less that 16MB would make for a very sub-par experience – astonishingly excessive for the time.
Development was famously led by DEC's Dave Cutler, who joined Microsoft five years earlier, with the goal of making the operating system portable via a common code base and a Hardware Abstraction Layer to do all the grungy low-level stuff. Non-Intel architectures such as DEC's Alpha were initially supported but later dropped. Support for POSIX and OS/2 APIs was also present, but faded away as the Windows juggernaut rode into town.
The current Arm incarnation of Windows 10 owes some debt to the early work of the Windows NT 3.1 team.
While initially not as wildly successful as its Windows/MS-DOS stablemate, Windows NT 3.1 (Server and Workstation) provided a solid basis that would eventually eclipse its legacy sibling. Unfortunately, it took some time before application vendors ported their wares over to the new OS (many were likely hedging their bets and waiting to see what IBM would do with its OS/2) so Microsoft offered some modicum of backwards compatibility in the form of the slightly shonky NTVDM (NT Virtual DOS Machine.)
The NTVDM (also known as Windows on Windows, or WOW) allowed legacy applications to run as though on a DOS computer, except without access to protected areas of memory. The theory went that applications running in this subsystem could not take down the operating system if things went south, only the NTVDM itself. Alas, this protection also meant that a substantial number of applications (notably games) simply did not work because NT blocked access to the hardware.
Windows NT 3.1 initially matched its DOS-based sibling version number-wise, but stepped out of sync a year later with the launch of NT 3.5, and then 3.51. NT 4, in 1996, is peak Windows as far as this grizzled hack is concerned, before NT was retooled for consumers with the launch of Windows XP in 2001.
It was 25 years ago that Microsoft made a determined effort to break with the past, and ditch backwards compatibility in order to modernise its operating system offering. If the cruft that has built up in the OS in the intervening years is to be dealt with, Redmond will need to repeat the process. ®