Is there a REST based ORM?

I've been looking at JavaScriptMVC, and I'm pretty interested in the idea. I'm wondering, though, if there are any ORM solutions for such an architecture. It seems like you will end up having to write two data access layers, one server side to fetch items from the database and one on the client side to retrieve items via AJAX.

My question is, are there any existing (preferably open source) solutions that would let me define a model (XML or class definition) and generate a REST api for me to access my data. I've been looking at DataMapper while I'm thinking about this, and it would be great if create a model, and instead of calling Person.all(:age.gt => 30) like I would in ruby I could just query /Person/All/?filter="age>30" (properly escaped of course) and get back an object serialized to XML without having to write the controller myself.

Is there anything out there like this? Does this seem like an intelligent way to go about fram开发者_运维问答ing a javascript based app?

After some more research, I think I've found my answer. Using CouchDB I can have all of the application logic running in the clients browser and use the built in REST api to persist the data to the server. This way, I could even manage the model in the client side javascript.