Are you aware of EDN, Transit or Fressian, which IMO improve a lot on the currently common approaches to encoding (JSON / YAML)? If so, how does Concise Encoding differentiate itself?
Yes, I've looked at EDN before. It's solving a similar problem, but not the same one. EDN is focused on extensibility, where as Concise Encoding is focused on concision, and binary-text compatibility.
Transit is a bridging format to other encoding formats, which is very cool, but a fairly different problem space.
Fressian is pretty close, but is binary only. The main purpose of Concise Encoding is binary-text compatible formats.
https://github.com/edn-format/edn
https://github.com/cognitect/transit-format
https://github.com/Datomic/fressian/wiki