Microsoft Corporation (NASDAQ: MSFT) is an American multinational corporation headquartered in Redmond, Washington, United States that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions. Established on April 4, 1975 to develop and sell BASIC interpreters for the Altair 8800, Microsoft rose to dominate the home computer operating system market with MS-DOS in the mid-1980s, followed by the Microsoft Windows line of operating systems.

Microsoft would also come to dominate the office suite market with Microsoft Office. The company has diversified in recent years into the video game industry with the Xbox and its successor, the Xbox 360 as well as into the consumer electronics and digital services market with Zune, MSN and the Windows Phone OS. The ensuing rise of stock in the company's 1986 initial public offering (IPO) made an estimated three billionaires and 12,000 millionaires from Microsoft employees (Forbes 400 list revealed that in March 2011 both Jon Shipley and Nathan Myhrvold lost their billionaire status). In May 2011, Microsoft Corporation acquired Skype Communications for $8.5 billion.

Primarily in the 1990s, critics contend Microsoft used monopolistic business practices and anti-competitive strategies including refusal to deal and tying, put unreasonable restrictions in the use of its software, and used misrepresentative marketing tactics; both the U.S. Department of Justice and European Commission found the company in violation of antitrust laws. Known for its interviewing process with obscure questions, various studies and ratings were generally favorable to Microsoft's diversity within the company as well as its overall environmental impact with the exception of the electronics portion of the business.