Personally I'm partial to http://jschema.org/ http://jschema.org/ (also see http://jschema.org/rpc.html http://jschema.org/rpc.html) because it seems simpler.

Personally I'm partial to http://jschema.org/ http://jschema.org/ (also see http://jschema.org/rpc.html http://jschema.org/rpc.html) because it seems simpler. My naive impression is that JSON-Schema is trying to be just like XML Schema, but in JSON. Which doesn't seem like a good thing.