DOS

DOS is a family of disk based operating systems for IBM PC compatible computers, made up mainly of IBM PC DOS and a rebranded version distributed by Microsoft as MS-DOS, both introduced in 1981. Compatible systems from other manufacturers followed, including DR-DOS in 1988, ROM-DOS in 1989, PTS-DOS in 1993, and FreeDOS in 1994, with MS-DOS dominating the IBM PC compatible market between 1981 and 1995. The name DOS is a platform independent acronym for disk operating system that predates the IBM PC and has also been used by unrelated systems such as the 1966 mainframe DOS/360, Apple DOS, Commodore DOS, and AmigaDOS. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/