Callook.info vs Wikidata

Callook.info is a free, keyless lookup service for FCC-licensed US amateur radio callsigns, returning license status, operator class, name, and registered address as either JSON or XML. A live request for a real callsign returns a wildcard Access-Control-Allow-Origin header with no authentication required, confirming it's safe to call directly from browser code.

Wikidata's action API exposes the structured, multilingual knowledge base behind Wikipedia's infoboxes — entity search, full item/property retrieval, and SPARQL-style queries over billions of statements. All read operations (wbsearchentities, wbgetentities, wbgetclaims, and friends) are keyless; OAuth only comes into play for authenticated edits/writes, which this directory entry isn't about. CORS is opt-in per request via the documented `origin=*` query parameter, which returns a wildcard Access-Control-Allow-Origin.