JSON is a fantastic format, anywhere people in your organization want to reach for XML, it's always a good thing to ask the question "Why not JSON?". The question I'd like you to ask the next time you're reaching for your JSON hammer, is "Why not MessagePack?". 

MessagePack has the following things going for it when compared to JSON.

1. JSON Compatible: Anything that works with JSON will work with MessagePack.
2. More space efficient: MessagePack uses an extremely efficient binary serialization format, for things like numbers and binary data MessagePack can be hugely more efficient. For use in persisting datastructures in something like Redis, where you want to be careful with memory usage, this is quite useful
3. Faster: MessagePack is usually much faster to encode / decode than JSON.
4. Supports Your Language: Ruby, Python, Perl, Javascript, PHP, Java, C++, C#,Go, Erlang, Haskell, OCaml, Scala, Clojure, and more all support MessagePack.
5. RPC: There's a separate MessagePack RPC project that maintains a high performance MessagePack based RPC server and client available in most of the languages above.

For the record, I'd probably still use JSON for a public facing API in most cases, but for internal ones, MessagePack generally wins.

The following example, written in Ruby, illustrates the advantages of MessagePack in action:

For more info, check out the Message Pack Website.

Loving byobu terminal for dev at the moment. It's like a super-nice, and sanely configured screen.