Microsoft Corporation is an American multinational corporation and technology conglomerate headquartered in Redmond, Washington. Founded in 1975, the company became influential in the rise of personal computers through software like Windows, and the company has since expanded to Internet services, cloud computing, video gaming and other fields. Microsoft is the largest software maker, one of the most valuable public U.S. companies, and one of the most valuable brands globally. Microsoft was founded by Bill Gates and Paul Allen to develop and sell BASIC interpreters for the Altair 8800. It rose to dominate the personal computer operating system market with MS-DOS in the mid-1980s, followed by Windows. During the 41 years from 1980 to 2021 Microsoft released 9 versions of MS-DOS with a median frequency of 2 years, and 13 versions of Windows with a median frequency of 3 years. The company's 1986 initial public offering and subsequent rise in its share price created three billionaires and an estimated 12,000 millionaires among Microsoft employees. Since the 1990s, it has increasingly diversified from the operating system market. Steve Ballmer replaced Gates as CEO in 2000. Wikipedia