In general, the subject matter described in this specification can be embodied in methods, systems, and program products for receiving a request to retrieve electronic resources that correspond to a first network address. The resources are retrieved from a cache. The retrieved resources are responsive to the request, correspond to the first network address, and are configured to activate a first web application. Activation of the first web application requires that the computing device be authenticated. Instructions that are in the retrieved resources and are for activating the first web application are executed. The execution includes determining that the computing device is not authenticated to activate the first web application, and requesting to retrieve electronic resources that correspond to a second network address and that are configured to activate a second web application. Activation of the second web application does not require that the computing device be currently authenticated.