Library of Congress Subject Headings

  1. Web publishing
  2. World Wide Web
  3. Affiliate programs (World Wide Web)
  4. Web portals
  5. Web search engines
  6. Internet users
  7. Internet marketing
  8. Web sites--Directories
  9. World Wide Web--Subject access
  10. Web servers
  11. Web sites
  12. Internet searching
  13. Web archives
  14. Online dating
  15. Electronic journals
  16. Worldwide Military Command and Control System

Search results are also available in RDF and JSON using content negotiation: 

          curl --header "Accept: application/rdf+xml" http://lcsh.info/search?q=Web
          curl --header "Accept: application/json" http://lcsh.info/search?q=Web

Valid XHTML + RDFa