1. A graphical user interface for viewing relationships among media objects in an editing system, wherein the media objects are defined using a plurality of classes, and wherein media objects in each class have a bidirectional relationship defined with media objects in other classes, and wherein each media object may have a plurality of relationships with media objects in other classes, the graphical user interface comprising: a first pane; a second pane associated with the first pane; means, operative in response to selection of one or more media objects and a selected relationship, for identifying media objects having the selected relationship with the selected one or more media objects; and means for displaying the selected one or more media object and the identified media objects in the first and second panes according to the relationship between the media objects.