The Semantic Web provides a common framework that allows data to be shared and reused across application, enterprise, and community boundaries. It is a collaborative effort led by W3C with participation from a large number of researchers and industrial partners. It is based on the Resource Description Framework (RDF).
The World Wide Web Consortium released GRDDL and GRDDL Test Cases as Recommendations. GRDDL enables authors to extract data from their documents automatically, enabling them to reuse their data and enrich it by connecting to the Semantic Web. A W3C GRDDL Service has also been installed; give it a try!