simple PHP code sample to serve backbone.js

Experience level: newbie.

The backbone.js Todos demo uses localStorage. This question is about how to use PHP to serve the page instead, assuming that a MySQL DB has been set up.

I checked out PHP frameworks such as CodeIgniter but found them difficult to follow and possibly overkill for my learning purposes.

I understand the concept that a REST API needs to be set up. I am really looking for simple code samples. Thanks in advance.

Update: Is there a full backbone.js tutorial somewhere that includes a full working example of how to wire up to server side PHP?