Computer software programmer and business pioneer. Born William Henry Gates, III, on October 28, 1955, in Seattle, Washington. The son of a lawyer and a schoolteacher, Gates began to show an interest in computer programming at the age of 13 at the Lakeside School. Two years later, he created a device that could analyze traffic patterns with fellow student Paul Allen.

Gates went to Harvard University in 1973. He had developed his first product while there—a program language for the first microcomputer called BASIC. Gates dropped out of Harvard in his junior year. He wanted to spend his time creating software, not in the classroom. In 1975, he founded Micro-Soft (later changed to Microsoft) with his longtime friend Paul Allen. Along with BASIC, Gates worked on the company’s next big product called DOS, which is a basic operating system.

DOS led to the company’s first huge success. In 1980, Gates made a deal with International Business Machines (IBM) to create a version of DOS for its line of personal computers. Soon DOS was the main operating system used by computer makers, making Microsoft a huge success and Gates a very wealthy man. The first version of the Windows operating system debuted in 1985 and it eventually became the leading system. By this time, the company had more than 1,000 employees and $200 million in sales.