Lawful.ly is a site that attempts to crowdsource legal knowledge by allowing people to annotate texts & then share their annotations with others, who may be seeking out explanations of certain legal terms or phrases.
It allows users to annotate legal agreements, forms, statutes, and case opinions. Then visitors to the Lawful.ly site can look up certain types of documents and click on annotated parts of the official text to read the notes & explanations that other users have left.