Microsoft is the world’s largest software company by market capitalization. Its enormous valuation reflects the strength of its Windows, Office, Azure, and enterprise-software businesses, along with investor expectations for continued cloud and artificial-intelligence growth.
Founded in 1975 by Bill Gates and Paul Allen, Microsoft first became famous for licensing MS-DOS and later developing Windows for personal computers. Office applications such as Word and Excel helped make it a dominant software provider for businesses, schools, and households.
A common mix-up is confusing Microsoft with Apple or Alphabet. Apple is primarily classified as a hardware and consumer-technology company, while Alphabet is mainly associated with internet services and advertising. Microsoft’s market capitalization can change daily, but among companies principally identified with software, it is the canonical answer to this question.