Trademark An operating system with a graphical user interface, released by Microsoft in 1993. Despite its superficial similarity to Windows, it used an entirely different codebase that was not constricted (as were Windows, Windows 95, and their successors) by an MS-DOS heritage. It was therefore able to fully exploit the hardware available at the time to create a much more secure and stable system with better multitasking capabilities. Windows NT (NT stood for new technology) was available in a standard and server versions, and was particularly aimed at the file-server market. Version 4.0, released in 1996, became the basis of many networks and continued in use long after Microsoft released subsequent versions of Windows. These versions — Windows 2000, Windows XP, and Windows Vista — are all developments of Windows NT.