William Henry Gates III (born October 28, 1955) is an American businessman and philanthropist. A pioneer of the microcomputer revolution of the 1970s and 1980s, he co-founded the software company Microsoft in 1975 with his childhood friend Paul Allen. Following Microsoft's initial public offering in 1986 and the subsequent increase in its stock price, Gates became the world's then-youngest billionaire in 1987, at age 31. Forbes magazine ranked him as the world's wealthiest person for 18 out of 2...