Zend_Application_Resource_Modules is used to initialize your application modules. If your module has a Bootstrap.php file in its root, and it contains a class named Module_Bootstrap (where "Module" is the module name), then it will use that class to bootstrap the module. By default, an instance of Zend_Application_Module_Autoloader will be created for the module, using the module name and directory to initialize it. Since the Modules resource does not take any arguments by default, in order to enable it via configuration, you need to create it as an empty array. In INI style configuration, this looks like: In XML style configuration, this looks like: