1. A computer-implemented method comprising: receiving, from a state processor and by each of a plurality of application processors, state data associated with a particular state of an application interface for an output display, wherein: a plurality of display devices are each arranged to produce a respective output portion of the output display, and each of the plurality of application processors is associated with and controls a respective one of the plurality of display devices; providing, by each of the plurality of application processors to each of their respective display devices, a display control signal to produce the respective output portion of the output display for the particular state of the application interface for the output display; receiving, from the state processor and by each of the plurality of application processors, a message indicating detected user interaction with the output display; determining, by each of the plurality of application processors, whether the detected user interaction affects the respective output portion of the output display produced by the display device that is controlled by the application processor; and providing, by the one or more application processors that are determined to control a display device that produces a respective output portion of the output display that is affected by the detected user interaction, an update control signal to the display device that is controlled by the application processor in order to update the respective output portion of the output display.