Wikipedia
DBpedia
DBpedia (from "DB" for " database") is a project aiming to extract structured content from the information created as part of the Wikipedia project. This structured information is then made available on the World Wide Web. DBpedia allows users to semantically query relationships and properties associated with Wikipedia resources, including links to other related datasets. DBpedia has been described by Tim Berners-Lee as one of the more famous parts of the decentralized Linked Data effort.