Procederual User Interface (UI), trough an option, possibly below the Planet Studio editor, this procederual editor would have sections to choose from (example the map, or building editor), and you can change the aspects of it and see the changes ocurring in a fixed template.
Examples of UI change via XML, screenshots sent by SupremeDorian, RDAsher, Aram and Brixxter.
@Rafaele ok