Bill Gates (born 1955), US business executive and computer engineer. Gates made his fame and fortune in the personal computer boom of the 1980s. His company, Microsoft Corporation, produced operating systems (MS-DOS) and application programs (Windows) that became the World standard for so-called IBM-compatible computers. Microsoft Corporation is the World's leading software company, and Gates himself became the youngest billionaire when he was just 31 years old. (1995).