Some example of Backbone and AMD for SO question

gistfile1.js

// file: models/Task.js
define([], function(){
	
	var Task = Backbone.Model.extend({
		//do stuff
	});
	
	return Task;
});

// file: collections/Tasks.js
define(['models/Task'], function(TaskModel){
	
	var Tasks = Backbone.Collection.extend({
		model: TaskModel
	});
	
	return new Tasks();
});

// file: views/TaskList.js
define(['collections/Tasks'], function(Tasks){
	
	var TaskList = Backbone.View.extend({
		render: function(){
			_.each(Tasks.models, function(task, index){
				// do something with each task
			});
		}
	});
	
	return new TaskList();
});


// file: views/statistics.js
define(['collections/Tasks'], function(Tasks){
	
	var TaskStats = Backbone.View.extend({
		el: document.createElement('div'),
		
		// Note that you'd have this function in your collection normally (demo)
		getStats: function(){
			totals = {
				all: Tasks.models.length
				done: _.filter(Tasks, function(task){ return task.get('done'); });
			};

			return totals;
		},
		
		render: function(){
			var stats = this.getStats();
			
			// do something in a view with the stats.
		}
	});
	
	return new TaskStats();
});

// file: views/App.js
define(['views/TaskList'], function(TaskListView){
	
	var App = Backbone.View.extend({
		el: '#app',
		
		initialize: function(){
			_.bindAll(this, 'render');
		},
		
		render: function(){
			TaskListView.render();
		}
	});
	
	return new App();
});

// called in index.html
Require(['views/App'], function(AppView){
	window.app = AppView;
});