Paul Allen was a visionary American entrepreneur and philanthropist. He is best known as the co-founder of Microsoft Corporation, alongside Bill Gates in 1975. The question tests knowledge about prominent figures in the technology industry. Paul Allen’s key association is with Microsoft. After leaving Microsoft in 1983 due to health issues, Allen founded Vulcan Inc., a private company that managed his various business and philanthropic efforts. He was also the owner of several professional sports teams, including the Seattle Seahawks (NFL) and the Portland Trail Blazers (NBA), and a part-owner of the Seattle Sounders FC (MLS).