1975
Microsoft (then spelled “Micro Soft”) is founded by William “Bill” Gates, a 20-year-old Harvard dropout, and Paul Allen, his 22-year-old school chum. They begin selling its first product, a BASIC programming language interpreter.
1980
Microsoft signs an agreement to build the operating system that became known as MS-DOS for IBM’s new personal computer, which was launched in 1981. Microsoft was allowed to license the operating system to others, spawning an industry of “IBM-compatible” machines dependent on Microsoft software.
1983
February: Paul Allen, ill with Hodgkin’s disease, resigns from active management of the company but remains on the board of directors.
1986
March 13: Microsoft’s stock goes public with an initial price of $21 a share, closing the first day of trading at $28. Revenue for its previous fiscal year (which ended June 1985) $140.4 million.
1989
August: Microsoft introduces earliest version of its “Office” software suite, which includes the popular word processing program “Word”. Today, the company says it has more than 500 million users.
