Yah, I've used some lame-assed JSON parsers whose authors thought they knew it well enough in their head that they didn't bother looking at the nice spec that laid it all out for them in black and while.
Maybe you mean http://web.archive.org/web/20030228034147/http://www.crockfo...? That has a context-free grammar (which omits the syntax for literals), railroad diagrams (which includes it), a prose description, an example JSON document, and a public-domain sample implementation in Java. It's true that there are some holes in the spec, notably the definition of whitespace and the semantics, but it's fairly complete and unambiguous.
