When asked about great developer communities, the site on the tip of everyone's tongue was Stack Overflow. This unique repository of programming insights is free, open, and maintained by the community that creates it.
The site envisions itself as part wiki, part social news aggregator (a la Digg), part blog, and part forum. And its appeal is universal — as the Stack team touts, "No matter what programming language you use, or what operating system you call home — better programming is our goal."
There seem to be two components of Stack's success. Many note that one is search.
"I find that more and more of my Google searches for issues return questions and answers in Stack Overflow," said Keir Whitaker, editor of the Think Vitamin blog at Carsonified.
The second component is Stack's strong community structure. "[T]he social media element is the participation of other users," Whitaker added. "The ability to vote up and down (but only down when you have sufficient reputation points) means that the quality of answers is generally high."
Whitaker noted that because Stack's platform is so useful and highly regarded, the team has made it available for other communities (stamp collectors, beer brewers, etc.) to take advantage of, via Stack Exchange Sites.