"Programmers all over the world helped make an American Dream happen in 2008 when we built Stack Overflow, a Q&A website for programmers creating a shared > Creative Commons knowledge base for the world. We did it democratically, because that's the American way. We voted to rank questions and answers, and held elections for community moderators using ranked choice voting. We built a digital democracy – of the programmers, by the programmers, for the programmers. It worked."

I don't know if StackOverflow should be his legacy. The site has become very heavy handed in moderation. The satellite sites are better (not SuperUser or the other one).