Core JSON: The Fat-Free Alternative to XML by Tom Marrs.
From the webpage:
JSON (JavaScript Object Notation) is a standard text-based data interchange format that enables applications to exchange data over a computer network. This Refcard covers JSON syntax, validation, modeling, and JSON Schema, and includes tips and tricks for using JSON with various tools and programming languages.
I prefer XML over JSON and SGML over XML.
Having said that, I have to agree that JSON is a demonstration that complex protocols for the interchange of data are unnecessary.
At least if you only care about validation and not the documenting the semantics of the data being interchanged.
Put another way, semantics are never self-evident or documenting. With JSON, some other carrier has to delivery semantics, if at all.
Topic maps are great carriers of semantics, particularly if you use JSON schemas or data files from multiple sources.
BTW, you will note that JSON is based on those pesky tuples that Robert Barta makes so much of. 😉