A demonstration of using Handlebars with Backbone.Marionette. Utilizes Grunt.js task (grunt-contrib-handlebars) to pre-compile templates, and swaps Handlebars.runtime for further optimization. Feel free to comment if you have any suggestions or questions!

app.js

define([
  'marionette',
  'templates'
], function(Marionette, Templates) {
  
  var app = new Marionette.Application({
    root: '/',
    templates: Templates
  });
  	
  return app;
});

config.js

require.config({
  deps: ['main'],
  paths: {
    jquery: '../vendor/js/libs/jquery',
    underscore: '../vendor/js/libs/lodash.underscore',
    backbone: '../vendor/js/libs/backbone',
    handlebars: '../vendor/js/libs/handlebars',
    
    marionette: '../vendor/js/libs/backbone.marionette',
    text: '../vendor/js/libs/text',
    hbars: '../vendor/js/libs/hbars'
  },
  shim: {
    handlebars: { exports: 'Handlebars' },
    marionette: {
      deps: ['jquery', 'underscore', 'backbone'],
      exports: 'Marionette'
    }
  }
});

grunt.js

module.exports = function(grunt) {
  grunt.initConfig({

    handlebars: {
      "dist/debug/templates.js": ["app/templates/**/*.html"]
    },

    requirejs: {
      mainConfigFile: "app/config.js",
      out: "dist/debug/require.js",
      name: "config",
      wrap: false,
      paths: {
        handlebars: "../vendor/js/libs/handlebars.runtime"
      }
    }
  });

  grunt.registerTask("debug", "handlebars requirejs");
};

hbars.js

define(['handlebars'], function(Handlebars) {
  var buildMap = {};

  return {
    load: function (name, parentRequire, onload, config) {
      if (config.isBuild) {
        var fsPath = config.dirBaseUrl + '/' + name + '.html'; // TODO - add ext into config options
        buildMap[name] = nodeRequire('fs').readFileSync(fsPath).toString();
        onload();
      }
      else {
  	var JST = window.JST ? window.JST : {};
        var path = 'app/' + name + '.html'; // TODO: add path into config options
	
        if (JST[path]) {
          // Grunt.js pre-compiles templates into JST[]
          onload(Handlebars.template(JST[template]));
        } else {
          // use text.js plugin when loading templates during development
          parentRequire(['text!' + name + '.html'], function(raw) {
            onload(Handlebars.compile(raw));
          });
        }
      }
    }
  };
});

module.js

define([
  'app'
], function(app) {
  var Module = app.module('Module');
  
  Module.Views = {};
  
  Module.Views.Index = Backbone.Marionette.ItemView.extend({
    template: app.templates.ModuleTemplate
  });
  
  return Module;
});

templates.js

define(function(require){
  return {
		
    // Layout/Region templates
    AppLayout: require('hbars!templates/layout_app'),
    
    ModuleTemplate: require('hbars!templates/module_template')
  };
});