The graphical BBQ (Blended Browsing and Querying) user interface allows to define complex XML queries in an elegant and intuitive way, based on the view DTDs provided by the mediator:
The main windows of BBQ are: The condition and answer windows are used for query composition, and define the head and the body of the generated XMAS query, respectively. The actual answers returned through the mediator are displayed in a separate window and can be browsed in the usual way. Since the retrieved answers are valid XML documents, they can be queried through BBQ as well. In this way, BBQ smoothly integrates browsing and querying of XML data.