Thanks, that's interesting to know. Given that we have json schema now though, what reason would someone use XML over Json now?
replyJSON is structured (not plain text to be analyzed by an IA).
JSON has JSON Schema.
replyIn addition, JSON is easier to parse and to map to common data structures of programming languages.
JSON Schema is an unofficial spec with a bunch of competitors and multiple versions, not all of which are compatible. I don't think you can compare it to XML schema validation.
replyI'm also not so sure about JSON being easier to map to common data structures. The lack of order guarantees within objects makes things like ordered maps quite annoying (you need to either use an array of entries with key and value, or an index within the mapped objects).