Paul Graham is a computer programmer who built early ecommerce software Viaweb in 1995 and sold to Yahoo for an estimated $49 million, whereupon it became Yahoo Stores.
 
With Jessica Livingston, Graham cofounded Y Combinator, a seed accelerator in Mountain View, Calif. that invests small amounts in founding teams and provides three-month boot camps in exchange for 2-10% equity.
 
Livingston was previously VP of marketing at an investment bank and is author of Founders at Work: Stories of Startups' Early Days. The couple was married in 2008.