Wikidata is built mostly on RDF ideas. For example, there's SPARQL query interface for it: https://query.wikidata.org/ https://query.wikidata.org/ Schema.org i

Wikidata is built mostly on RDF ideas. For example, there's SPARQL query interface for it: https://query.wikidata.org/ https://query.wikidata.org/ Schema.org is heavily used by search engines and metadata in its format is found on many websites. It's an RDF-based format.