Founder, chairman of Microsoft; founder and co-chair of the Bill & Melinda Gates Foundation
Bill Gates remains the iconic technologist, entrepreneur, and business leader of his generation. He invented the software industry, masterminded the rise of the PC, and has hung in there as a force on the Internet. Still intent upon transforming how people work and communicate, now Gates is pushing software to handle all aspects of office communications, from your phone to e-mail to instant messaging. His software powers smartphones and will show up soon in television set-top boxes. And he has hooked up with upstarts like Facebook to channel the energy and advertising potential of social networks.
Since 2000 he's had a new kind of power through the charitable activities of the Bill & Melinda Gates Foundation. Gates is expected to retire from Microsoft next year and devote most of his time to the foundation, which has an endowment of $33 billion - and the promise of tens of billions more from his close friend and occasional bridge partner Warren Buffett (No. 5). The foundation has global aspirations to improve health care and reduce poverty. His other goal: reinventing philanthropy itself, much as he did information technology. --Brent Schlender