MS-DOS

An example of MS-DOS's command-line interface, this one showing that the current directory is the root of drive C.
Company/
developer: Microsoft Corporation
OS family: DOS
Source model: Closed source
Latest stable release: 8.0 / September 14, 2000
Marketing target: ?
Available language(s): C, Pascal, QBasic, etc.
Supported platforms: x86
Kernel type: Monolithic kernel
Default user interface: Command line interface, Text user interface
License: Proprietary
Working state: Discontinued
MS-DOS (short for Microsoft Disk Operating System) is an operating system commercialised by Microsoft. It was the most commonly used member of the DOS family of operating systems and was the dominant operating system for the PC compatible platform during the 1980s. It has gradually been replaced on consumer desktop computers by various generations of the Windows operating system.

MS-DOS was originally released in 1981 and had eight major versions released before Microsoft stopped development in 2000. It was the key product in Microsoft's growth from a programming languages company to a diverse software development firm, providing the company with essential revenue and marketing resources. It also provided the platform on which early versions of Windows ran.