Bill Gates is co-chair of the Bill & Melinda Gates Foundation, which works to expand opportunity to the world’s most disadvantaged people, and co-founder and former chair of Microsoft. Gates started Microsoft with Paul Allen in 1975, leading the tech company until 2000, when he became its chief software architect. He left his day job and transitioned into the chairman role in 2008, also serving as a technology advisor. Gates is also co-founder of the Giving Pledge, a commitment to give more than half of one’s wealth to philanthropic causes or charity. In 2015, he created the Breakthrough Energy Coalition, a group committed to clean energy innovation, followed by Breakthrough Energy Ventures in 2016, an investor-led fund providing capital to clean energy companies, which he chairs.