Described is an architecture by which application programs can provide data to auxiliary display devices of essentially any type for display to a user. A defined application layer (e.g., accessed via interfaces) allows programs to provide data to a service that controls the output of data to an auxiliary display device, and returns navigational data to the application upon appropriate user interaction with the device via actuators. Enumeration allows applications to discover the capabilities of a device, while arbitration determines which application has input-output rights to the device. The architecture further provides a protocol layer including pluggable protocol proxies that allow various types of displays to serve as an auxiliary display. This platform-like model allows program developers the ability provide programs that leverage auxiliary displays when available, and provides display manufacturers the ability to provide displays with extensible capabilities.