LV2 audio plugins use RDF/Turtle;

https://github.com/lv2/lv2

  curl -H "Accept: text/turtle,application/rdf+xml" http://lv2plug.in/ns/ext/lv2core
  curl -H "Accept: text/turtle,application/rdf+xml" http://lv2plug.in/ns/ext/atom

Some hosts also use it for saving audio graphs;

https://drobilla.net/software/ingen.html http://drobilla.net/ns/ingen.html

https://github.com/moddevices/mod-factory-user-data/tree/mas... https://pedalboards.moddevices.com/