Who co-founded Microsoft with Bill Gates?

Paul Allen co-founded Microsoft with Bill Gates in 1975. The two childhood friends formed the company after developing a BASIC interpreter for the Altair 8800, an early personal computer made by Micro Instrumentation and Telemetry Systems (MITS).

Allen helped create the opportunity by spotting the Altair on the cover of Popular Electronics in January 1975. Gates and Allen then built and demonstrated their interpreter to MITS in Albuquerque, New Mexico. MITS agreed to distribute it as Altair BASIC, giving the new company its first important product.

Allen suggested the name “Micro-Soft,” combining “microcomputer” and “software.” He left the company’s day-to-day operations in 1983 after receiving a Hodgkin lymphoma diagnosis, although he remained connected to Microsoft and its leadership. Steve Ballmer later became a major executive, but he was not a co-founder.