William Henry Bill Gates III (born October 28, 1955), is an American business magnate, philanthropist, the worlds third richest person (as of February 8, 2008), the second richest American (as of October 10, 2008), and chairman of Microsoft, the software company he founded with Paul Allen. During his career at Microsoft, Gates held the positions of CEO and chief software architect, and remains the largest individual shareholder with more than 8 percent of the common stock. He has also authored or co-authored several books.