1. A computing system, comprising: two or more separate input-device user-interface runtime applications without system-wide active focus to dynamically display images on a dynamic input device, the two or more input-device user-interface runtime applications configured to independently execute within a windowless runtime environment configured to execute in a currently active desktop; and a dominant desktop application with system-wide active focus configured to execute outside of the windowless runtime environment in the currently active desktop, the dominant desktop application configured to specify from the two or more input-device user-interface runtime applications an input-device user-interface runtime application corresponding to a current context of the dominant desktop application, and the specified input-device user-interface runtime application configured to dynamically display virtual controls on the dynamic input device and report activation of the virtual controls to the dominant desktop application while the specified input-device user-interface runtime application does not have system-wide active focus.