Gabe Newell left Harvard to join Microsoft, where he worked on early Windows releases and a Windows 95 port of Doom. In 1996 he co-founded Valve, led development of Half-Life and built Steam into the dominant PC game platform. He now owns Valve and several research ventures, and is one of the richest figures in gaming.

• Gabe Newell went from dropping out of Harvard and working 13 years at Microsoft to co-founding Valve, whose Steam platform now controls up to 70% of PC digital game sales.
• Forbes estimates his net worth at roughly $11 billion in 2025, making him the richest person in the games industry.
• He's diversified into marine research (Inkfish), neural interfaces (Starfish Neuroscience), yacht manufacturing (Oceanco), and gave $20 million to OpenAI as an early informal advisor.
• He's funded children's hospital charities through efforts like Heart of Racing and launching a Half-Life gnome into space.