Bill Gates (William Henry Gates 3d), 1955–, American business executive, b. Seattle, Wash. At the age of 19, Gates founded (1974) the Microsoft Corp., a computer software firm, with Paul Allen. They began by purchasing the rights to convert an existing software package. In 1980 they agreed to produce the operating system for the personal computer being developed by International Business Machines (IBM). That system, MS-DOS (Microsoft Disk Operating System), and subsequent programs (including the Windows operating systems) made Microsoft the world's largest producer of software for microcomputers.
In 1997 the U.S. Justice Dept. accused Microsoft of violating a 1995 antitrust agreement, because the Windows 95 operating system required consumers to load Microsoft's Internet browser—thus giving Microsoft a monopolistic advantage over other browser manufacturers. In late 1999 the trial judge decided that Microsoft was a monopoly that had stifled competition, and the following June he ordered the breakup of Microsoft into two companies, a decision that Microsoft appealed. Although the appeals court overturned (2001) the breakup, it agreed that Microsoft had stifled competition and returned the case to a lower court for resolution. Subsequently the government and the company agreed to a settlement that placed some restrictions on Microsoft but would not essentially diminish the advantage its operating system monopoly gave the software giant; several states contested the settlement, but a judge approved it in 2002. In the European Union the company has also faced scrutiny over anticompetitive concerns, and there it has several times been fined hundreds of millions of euros.
Gates, who was long chairman of Microsoft, is one of the wealthiest persons in the world. In 1994 he founded the William H. Gates Foundation (focusing on health issues in developing countries) and in 1997 established the Gates Library Foundation, later renamed the Gates Learning Foundation (providing education assistance). In 1999 the former was renamed the Bill and Melinda Gates Foundation, and the latter was merged (2000) into it. In 2008 Gates, while remaining as company chairman, withdrew from daily participation in the running of Microsoft in order to devote more time to the foundation, but in 2014 he returned to a more active role at Microsoft, becoming an adviser to the company's chief executive while also stepping down as chairman. He has written The Road Ahead (1995, with N. Myhrvold and P. Rinearson) and Business @ the Speed of Thought (1999).
See J. Wallace, Hard Drive (1992).