This is a simple application that shows how to use the JavaScript/Backbone client library. Except for the JavaScript libraries the source for this application is contained entirely within this HTML document. Most of the code is for creating the GUI. The code for actually doing the REST request/response are in the form's submit callback and the function doRestRequest() and consists of only about 40 verbose lines of code.

This is an "extreme" example as this HTML document is not generated by WordPress. WordPress's role in this application is entirely just as a REST server. The page layout in Backbone applications can be handled by JavaScript code. A more typical application would use WordPress to generate the header, sidebar and footer and use a REST Backbone client to dynamically generate the post content.