> most programming languages internal memory representations

Often heard wrt JSON but incorrect. It maps to the primitive types in JavaScript. But almost all programming languages treat floats and integers different, make distinction between char and strings and many have some form of date/time. JSON has neither.

In that direction, XML is much closer since every node is a triple (name, value, attributes) so can have type info, json is a tuple. And Protobuf, while not popular, gets this completely right.