Paul Graham's logo

Paul Graham is the father of Y Combinator, a startup-rearing juggernaut that's part incubator, part drill sergeant and part liaison to the investor class. Y Combinator--a computer term for a program that runs other programs--has fired up 200 companies since 2005, jarred the balance of power between entrepreneurs and Silicon Valley's elite money, and chiseled a new paradigm for launching technology companies. Graham's formula: Get up and running (bugs and all), gather feedback, tweak and grow.