1. A computer-implemented method, the method comprising: receiving a user's definition of at least a user interface (UI) layout and a UI principle for one or more user interfaces, the UI principle comprising a UI rule associated with a mandatory UI behavior and the UI principle comprising a UI concept associated with a recommended UI behavior; creating a UI taxonomy that is an abstraction of a class of UIs consistent with the UI layout and the UI principle; generating a UI prototype using the UI taxonomy, the UI prototype being an instance of the class of UIs; providing the UI prototype for use in creating, in response to a user control, a UI for an application; automatically verifying whether the UI for the application complies with the UI rule; upon automatic verification that the UI for the application does not comply with the UI rule, automatically reformatting the UI for the application to comply with the UI rule; automatically verifying whether the UI for the application complies with the UI concept; and upon automatic verification that the UI for the application does not comply with the UI concept, performing a predefined action, the predefined action comprising generating a message stating how the UI for the application does not comply with the UI concept.