Microsoft was founded by Bill Gates and Paul Allen.
Gates and Allen established Microsoft in Albuquerque, New Mexico, in 1975. Their first major commercial project was a version of the BASIC programming language for the Altair 8800, an early personal computer kit. The company name originally appeared as “Micro-Soft” in 1975.
Paul Allen was a programmer and business partner who helped identify the opportunity created by the Altair. Gates supplied extensive programming expertise and became Microsoft’s long-serving chief executive, while Allen left his full-time role in 1983 after receiving a Hodgkin lymphoma diagnosis.
Microsoft later became central to personal computing through MS-DOS and Windows, then expanded into enterprise software, cloud computing, gaming, and hardware. Steve Ballmer joined later and succeeded Gates as chief executive, so he is not a co-founder.