Stack Exchange

Stack Exchange is a network of question-and-answer sites, each dedicated to a specific subject — from mathematics and physics to cooking, law and language.

Each site has its own community standards and voting, which keeps quality higher than general forums: answers are expected to be substantiated, and unsupported claims get corrected in public.

Stack Overflow, the programming site, is the largest by far, but the smaller sites are often where a well-researched answer to an obscure question actually exists.