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Engineer runners-up: Cheever and D'Angelo
Co-Founders, Quora

Founder Mark Zuckerberg isn't the only smart guy at Facebook. The social media giant has spawned a plethora of talented engineers, and several of them have since broken out on their own. In January, Facebook alums Charles Cheever, 28, and Adam D'Angelo, 25, launched Quora, a site where users pose questions that range from "When, how, and why did Journey's `Don't Stop Believing' get its second wind of popularity? to "How do you conceptualize an electron?" In March the company received funding (reportedly $11 million) led by Benchmark Capital. The site is built on the philosophy that people like to share not just information about themselves (viz. Facebook) but also knowledge. --B.K.

NEXT: Engineer runner-up: Luke Rajlich
Last updated July 09 2010: 1:19 PM ET