I'm not a Java coder so I'll take your word on it about library support, I've only used the JSONObject, JSONArray, etc. classes. Surely you will concede that JSON being modeled after JavaScript gives the language a little bit of a leg up?
Not really. In theory, it's an advantage in that you can reuse the parser and avoid loading another, but in practice, that's only really important in the browser, not on the server, where the lib will be permanently loaded anyway.
And JSON values map 1:1 to native data structures in most languages - in fact, JSON can be parsed as Python code with the exception of the \/ escape.
