Who was Bill Gates’s co-founder at Microsoft?

Bill Gates’s co-founder at Microsoft was Paul Allen.

Gates and Allen met as students at Lakeside School in Seattle, where they shared an interest in computers and programming. Allen was older than Gates and helped introduce him to the possibilities of writing software for emerging personal computers.

In 1975, the pair adapted BASIC for the Altair 8800, a project that became Microsoft’s first major commercial opportunity. Allen is credited with suggesting the name Micro-Soft, which was initially written with a hyphen.

Allen left his full-time position at Microsoft in 1983 after being diagnosed with Hodgkin lymphoma, though he remained a shareholder. He later became a major investor, philanthropist, and owner of professional sports teams. He died in 2018.