1. One or more computer-readable media comprising computer-executable instructions for generating a mapping between network content and applications, the computer-executable instructions performing steps comprising: obtaining, from network content, an application mapping document identifying one or more applications; obtaining, from one or more applications, a manifest identifying one or more collections of network content; generating a first mapping between a first collection of network content and a first application if both the first application comprises a manifest identifying the first collection of network content and if the first collection of network content comprises an application mapping document identifying the first application; and periodically repeating the obtaining the application mapping document and the obtaining the manifest.