Born on October 28, 1955, Gates and his two sisters grew up in Seattle. Their father, William H. Gates II, is a Seattle attorney. Their late mother, Mary Gates, was a schoolteacher, University of Washington regent, and chairwoman of United Way International.

Gates attended public elementary school and the private Lakeside School. There, he discovered his interest in software and began programming computers at age 13.

In 1973, Gates entered Harvard University as a freshman, where he lived down the hall from Steve Ballmer, now Microsoft's chief executive officer. While at Harvard, Gates developed a version of the programming language BASIC for the first microcomputer - the MITS Altair.

In his junior year, Gates left Harvard to devote his energies to Microsoft, a company he had begun in 1975 with his childhood friend Paul Allen. Guided by a belief that the computer would be a valuable tool on every office desktop and in every home, they began developing software for personal computers.

In 1999, Gates wrote Business @ the Speed of Thought, a book that shows how computer technology can solve business problems in fundamentally new ways. The book was published in 25 languages and is available in more than 60 countries. Business @ the Speed of Thought has received wide critical acclaim, and was listed on the best-seller lists of the New York Times, USA Today, the Wall Street Journal and Amazon.com. Gates' previous book, The Road Ahead, published in 1995, held the No. 1 spot on the New York Times' bestseller list for seven weeks.

Gates has donated the proceeds of both books to non-profit organizations that support the use of technology in education and skills development

In addition to his love of computers and software, Gates is interested in biotechnology. He sits on the board of ICOS, a company that specializes in protein-based and small-molecule therapeutics, and he is an investor in a number of other biotechnology companies.

Philanthropy is also important to Gates. He and his wife, Melinda, have endowed a foundation with more than $21 billion to support philanthropic initiatives in the areas of global health and learning, with the hope that as we move into the 21st century, advances in these critical areas will be available for all people.

Gates was married on Jan. 1, 1994, to Melinda French Gates. The couple has two children: a daughter, Jennifer Katharine Gates, born in 1996; and a son, Rory John Gates, born in 1999.