Meet the Facebook Mafia

Open Business Council
5 of 9

Dustin Moskovitz and Justin Rosentstein

Moskovitz was Zuckerberg's Harvard roommate and is the youngest person on Forbes's list of billionaires (he is eight days younger than his former boss). In November 2009, the Facebook co-founder left the company to co-found Asana, a workplace productivity start-up, with former Facebook engineer manager Justin Rosenstein. (Rosenstein is the man responsible for Facebook’s ubiquitous "Like" button.) Moskovitz owns 7.5% of Facebook, a stake that could be valued as high as $7.6 billion. To get Asana off the ground, he landed angel funding from Thiel and Parker, among other Silicon Valley notables.