Microsoft Flight Simulator is a series of flight simulator programs for MS-DOS, Classic Mac OS, and Microsoft Windows operating systems. It was an early product in the Microsoft application portfolio and differed significantly from Microsoft's other software, which was largely business-oriented. Microsoft Flight Simulator is Microsoft's longest-running software product line, predating Windows 1.0 by three years, and is one of the longest-running video game series of all time. Bruce Artwick began the development of Flight Simulator in 1977.
https://en.wikipedia.org/wiki/Microsoft_Flight_Simulator