I don't know about successful - Docker still has to prove that it can build a large sustainable business. Obviously I am bullish on the opportunity :)
I definitely was a complete outsider when I moved to Silicon Valley: first generation immigrant, with no affiliations or credentials whatsoever, no traction, and a lot of personal debt. If YC hadn't taken a chance on us and written that $17,000 check, we probably would have never made it this far. And I had it easy compared to other outsiders: I had US citizenship, my english doesn't betray I'm a foreigner, and of course I'm a white male.