Bill Gates is an American business magnate, software developer, and philanthropist best known as the co-founder of Microsoft, which he launched with Paul Allen in 1975. Gates played a pivotal role in the rise of personal computing, leading Microsoft to become the world's largest software company. Since stepping down from day-to-day operations, he has focused on global health, education, and climate initiatives through the Bill & Melinda Gates Foundation, one of the largest charitable organizations in the world.