1. A computer-implemented method, comprising: loading a first application using a first isolation environment provided by an application execution environment, the first application being designated to the first isolation environment; receiving a request from the first application to load a second application; determining that the second application consents to being loaded using the first isolation environment, the consent based at least in part on security policy information associated with the second application including an access control directive that specifies whether the first application is allowed to load the second application, said determining that the second application consents to being loaded using the first isolation environment includes matching the first isolation environment with the security policy information; loading the second application as playable media, playable by the first application, using the first isolation environment despite the second application being designated to a second isolation environment provided by the application execution environment; processing data using first instructions included in the first application and second instructions included in the second application, where the processing includes using the first instructions of the first application to invoke functionality provided by the second instructions of the second application; and outputting information based on a result of the processing.