A method, system and computer program product for downloading an application over a network from a remote server to a client device, where the application includes a plurality of modules. A class for each module is created, where the class includes a constructor. A request to use a module of the application is received. Upon receiving the request, a determination is made as to whether the received request is a first request to use the module. If the received request is the first request to use the module, then the requested module is downloaded, the constructor is overwritten with the downloaded module and the constructor within the created class for the requested module is executed.