Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA 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 dollars.