Urban Observatory vs Wikipedia

Urban Observatory, run by Newcastle University, streams one of the UK's largest real-time urban sensor networks, covering air quality, traffic, flooding, and weather, from thousands of fixed and mobile sensors across Newcastle and partner cities. Its v2 API is fully keyless and exposes sensor locations and readings as JSON, CSV, or Shapefile, with bounding-box filtering for GIS tools. It's an academic, publicly funded service with no commercial tiers.

The MediaWiki action API that powers Wikipedia gives keyless access to full-text search, page content/extracts, revision history, and category membership across every language edition. A live probe of en.wikipedia.org/w/api.php confirms open, keyless reads and resolves the CORS story: browsers must append the documented `origin=*` query parameter (a plain Origin header alone is rejected as a "mismatch"), after which the response carries a wildcard Access-Control-Allow-Origin.