Stack Overflow Clones?
Does this (stack overflow) forum has any open source code? And if no, can anyone please, give me an open source code engine site, that is similar to Questions & Answers idea, based on phP / MySql? I've tried Question2Answer and several others, but I like exactly this engine of Stack overflow, so I'm searching for a like alternatives. And if there's no free engine, does any one know if I can buy something similar to stack overflow idea.