A data structure including simple and complex objects. Each simple object includes a content type indicator, a size indicator, and one or more simple data types. Each complex object includes a content type indicator, a size indicator, and one or more child objects. The complex objects include a layer object having first and second child objects. The first child object is a collection of complex objects storing information for configuring a virtual filesystem of a virtual application at application startup. The second child object is a collection of complex objects storing information for configuring a virtual registry of the virtual application at application startup. Reading of selected simple and complex objects may be deferred at startup based on the content type indicator. Deferred objects may be read after startup when access to information stored by the deferred object is request by the virtual application.