While it's not quite what you want (as the specification language is not JSON---it's more like C declarations), "protobufs" allow you to generate serializers an

While it's not quite what you want (as the specification language is not JSON---it's more like C declarations), "protobufs" allow you to generate serializers and de-serializers in a number of languages. http://github.com/google/protobuf http://github.com/google/protobuf