EDN is excellent

The Haskell implementation is elite too

https://hackage.haskell.org/package/hedn

You beat me to it by seconds!

Lots over overlap here with Clojure’s Extensible Data Notation (edn).

It has extensibility by having `'{' blargh '}'` be "don't parse the content between the braces". That isn't meaningfully different from just using strings/CDATA in json/xml.

The `blargh` between braces also can't contain closing braces - so they're not even fully generic.

Also, personal pet peeve - it should have a way to specify floating point values in binary, as there are many floating point values with textual representations that are massive and/or don't have numeric representation (nan, infinity, signaling variants)

When someone writes "More extensible than XML", you know they've never truly seriously studied and used XML.

Looks very close to JavaScript.

I think JavaScript literal object notation might be a great choice for representing data. Then those who program in JS would have everything needed already?

That date formatting is horrible

Looks like a reinvention of NeXTStep's "Property Lists" (<https://en.wikipedia.org/wiki/Property_list>)