Microsoft just announced a new project called 'datajs'. datajs is a cross-browser JavaScript library that among other things brings comprehensive OData support to JavaScript. 'datajs' is an open source project, released under MIT.

For example if allows you to query an OData service like this:"", function (data, response) {
//success handler

And do inserts like this:

method: "POST",
requestUri: "http://ODataServer/FavoriteMovies.svc/BestMovies"
data: {ID: 0, MovieTitle: 'Up'}

function (data, response) {
//success handler

For more information check out the announcement