Bill Gates (born October 28, 1955, Seattle, Washington, U.S.) is an American computer programmer and entrepreneur who cofounded Microsoft Corporation, the world’s largest personal-computer software company.

Gates wrote his first software program at the age of 13. In high school he helped form a group of programmers who computerized their school’s payroll system and founded Traf-O-Data, a company that sold traffic-counting systems to local governments.