Compound controls

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for specifying a compound control. One of the methods includes identifying a first application. The method includes displaying a canvas. The method includes displaying, in the canvas, a first display object associated with the first application. The method includes identifying a second application, the second application being a computer executable program. The method includes displaying, in the user interface, a second display object associated with a second application. The method includes, in response to a user action that associates the second display object with the first display object, configuring the first application to invoke the second application. The method includes creating a third display object that includes the first set of selector objects and the second set of selector objects.