Microsoft, 1994. DOS.
MS-DOS was the main operating system for IBM PC compatibles through the 1980s. It began as 86-DOS, written by Tim Paterson at Seattle Computer Products. Microsoft hired Paterson in May 1981, bought 86-DOS, and licensed it to IBM, which offered it in August 1981 as PC DOS 1.0 for the IBM PC. Within a year Microsoft had licensed MS-DOS to more than 70 other companies.
At first each computer maker built its own MS-DOS, with drivers for its own hardware and a standard kernel from Microsoft. But programs, games especially, often controlled the hardware directly for speed, so PC makers soon copied IBM’s design closely, and one MS-DOS for IBM-compatible PCs was enough.
MS-DOS 6.0 and 6.20, released in 1993, included DoubleSpace disk compression. Stac sued Microsoft for patent infringement over its compression method and won, so in 1994 Microsoft released MS-DOS 6.21 with compression removed, and shortly afterwards 6.22 with DriveSpace, which used a different method. Version 6.22 was the last MS-DOS sold on its own. Versions 7 and 8 mostly worked in the background to load Windows 9x, and development ended in 2000.
On its way to the C:> prompt, this exhibit loads a CD-ROM driver with MSCDEX and two later programs: CuteMouse, a mouse driver from FreeDOS, and the CPU-idling program DOSidle.