Dynamic, set driven, ribbon, supporting deep merge

Displaying a ribbon user interface in a context dependant fashion. A method includes displaying a ribbon user interface. The ribbon user interface is associated with some set of user data and includes one or more displayed tabs. Each tab includes one or more groups that are displayed for a given tab. Each group includes one or more controls. Displaying a ribbon user interface includes displaying a single set of groups, and one or more sets of controls, one for each group, for a single tab that is selected. The method further includes receiving user input related to the user data resulting in a change of context related to the user data. Membership of at least one of the single set of groups or the one or more sets of controls is changed based on the change of context related to the user data.