EDN’s my favourite config format.

+ Simple (like JSON)

+ Has comments

+ Extensible

+ Built-in sets, UUIDs & timestamps

+ Well-suited to configuration (cf. Aero)

+ Lispy (well, Clojurey)

- Lispy (well, Clojurey)

- Handwavey specs

- Not widely supported

Would you please link an example, a specification, or something? I think I found something on GitHub, but it was not straightforward.