Bill Gates is co-chair of the Bill & Melinda Gates Foundation. As co-chair, he shapes and approves foundation strategies, advocates for the foundation’s issues, and sets the organization’s overall direction. He works with grantees and partners to further the foundation’s goal of improving equity in the United States and around the world. Bill co-founded Microsoft in 1975 with Paul Allen and led the company to become the worldwide leader in business and personal software and services. In 2008, Bill transitioned to focus full-time on his foundation’s work. Through his private office, Gates Ventures, he pursues his work in climate change and clean energy innovation, Alzheimer’s research and other healthcare issues, interdisciplinary education, and technology. He is also the founder of Breakthrough Energy, which works to address climate change by supporting the next generation of entrepreneurs, big thinkers, and clean technologies. In 2010, Bill, Melinda French Gates, and Warren Buffett founded the Giving Pledge, an effort to encourage the wealthiest families and individuals to publicly commit more than half of their wealth to philanthropic causes and charitable organizations during their lifetime or in their will.