Maybe I'm wrong, but it seems like the only thing missing from json is a standard for dealing with time, and a standard for dealing with typed objects/arrays. Wrap all that into a binary format and call it done. All these other additions seem like bloat to me designed for some specific language or use case.
A lot of tools for (almost) the same job, it seems.<p>I also like Zed Shaw's TNetstrings alternative: <a href="http://tnetstrings.org/" rel="nofollow">http://tnetstrings.org/</a><p>I like how it, indeed, is trivial to parse.
See also bert-rpc, which is a cross-language/platform serialization standard along with fast rpc support. This is what github uses:<p><a href="http://bert-rpc.org/" rel="nofollow">http://bert-rpc.org/</a>