The biggest corporate success stories in American history. From its humble beginnings in Bill Gates' Harvard dorm room, in only 35 years the company grew to become one of the biggest companies in the world.

The Numbers 1975: The year Microsoft was founded. The company was initially formed as the partnership Micro-soft, which operated for over five years until the firm was incorporated in 1981.Aug. 12, 1981: Microsoft releases its first personal computer running its operating system, MS-DOS 1.0.

4,000: The number of lines of code in MSDOS 1.0--Microsoft's first operating system. 50 million: The number of lines of code estimated to be in Microsoft Vista. Aug. 1, 1989: The first incarnation of Microsoft Office is released.9 cents: the March 13, 1986, Microsoft IPO price, as adjusted for stock splits.

10,000: The estimated number of Microsoft employees that became millionaires as a result of their stock ownership in the firm. 88,180: The number of employees as of April 2010.The number of countries where Microsoft has subsidiaries.

646: The number of office sites worldwide. Ninety-nine locations are owned by the company, with the remaining 547 under lease. 32,404,796: The total square feet owned or leased by Microsoft worldwide.

128: The number of companies that have been acquired by Microsoft as of the end of 2009.

$58 billion: Microsoft's fiscal year 2009 revenues.

40 million: The number of units of Microsoft's Xbox 360 gaming console sold worldwide. The major competitors in this market are Sony's ( SNE - news - people ) PS3, which sold 35.7 million units, and Nintendo's ( NTDOY.PK - news - people ) Wii, which sold 70.93 million units.
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5 million: The number of units of Microsoft's Zune music player sold. The Zune player has not performed as well as its chief competitor, the Apple ( AAPL - news - people ) iPod, which has sold over 260 million units. $1.4 billion: The fine paid to the E.U. in 2008 for not complying with a 2004 antitrust judgment. This judgment was the largest ever imposed against a single company by the E.U.'s competition regulators.

$1,276,627: Microsoft CEO Steve Ballmer's total compensation in 2009. Ballmer joined Microsoft in 1980, as its 24th employee. Ballmer is now the 33rd-wealthiest person in the world, with an estimated net worth of $14.5 billion, according to Forbes.

$53 billion: Microsoft cofounder Bill Gates' net worth. Gates is the second wealthiest person in the world, according to Forbes. Microsoft's other founder, Paul Allen, is the 37th-wealthiest person in the world, with a net worth estimated at $13.5 billion.