Freesound vs Radio Browser

Freesound's APIv2 lets apps browse, search, and retrieve Freesound's library of user-uploaded sound clips — with content-based similarity search and audio-analysis features on top of plain metadata search — plus upload, comment, rate, and bookmark actions for authenticated users. It supports both token-based key auth and full OAuth2, defaults to JSON responses (XML and YAML are available but untested by the maintainers), and access is free for registered developers. The older APIv1 has reached end-of-life and is no longer available.

Radio Browser is a free, keyless, community-maintained directory of internet radio stations — over 60,000 of them — with search, tagging by genre/country/language, click-tracking, and ready-to-play M3U playlists for any station. It's fully open source, mirrored across several independently-run servers behind a round-robin DNS entry point, and its maintainers explicitly ask API consumers to pick a random mirror rather than hammer one instance. Responses are available as JSON or XML, with a dedicated M3U format for playlist endpoints.