Customizing applications in a discovery interface

A system provides customized user interface data to a media application, such as a media discovery interface, or to any application for that matter, thereby extending the original application. Via a network connection, elements of the user interface can be downloaded to the application in a package of markup data and resources, including images, text, and links. A user interface framework of the media application processes the markup from the downloaded package and utilizes packaged resources, local code components, and externally-obtained (e.g., Web resources) to render a customized application page for the media application.