An example of how to get Backbone Models and Collections working in a firefox extension.

ffextension.js

var Request = require('request').Request,
  _ = require('./underscore'),
	Backbone = require('./backbone'),
	// Firefox Add-Ons cannot use jQuery in the background
	// script, but there are instances where we need some 
	// jquery functionality, paricularly $.ajax, which
	// is defined later.
	$ = {
		ajax: function (params) {
			if (!params.url){
				console.error('ajax request made without url');
				return false;
			}

			var util = this;

			params.onComplete = function (response) {
				// WARNING: response is read-only. 
				if (response.status === 200){
					params.success &&
					params.success(response.text, response.status, response);	
				}else{
					console.error('ajax request failed');
					params.error &&
					params.error({
						responseText: response.text,
						status: response.status	
					});
				}
			};
			Request(params).get();
		}			
	};

// use our pseudo-jQuery instead 
Backbone.setDomLibrary($);