Inside Bills Brain: Decoding Bill Gates 1of3 2019 History The series about the man, myth and legend - founder of Microsoft and co-founder of the Bill and Melinda Gates Foundation - reflects on his trailblazing work with computer software, starting the largest private philanthropic foundation. Bill Gates opens up about his childhood, business career and passion for improving the lives of people in the developing world. When Bill Gates stepped down from Microsoft in 2008, he was worth more than 58 billion dollars. He built that fortune thinking about computer software, operating systems, spreadsheets and the Internet. What was on his mind?