Users of NetBeans IDE 7.3 will find a significant usability enhancement caused by a redesign of the "inspect hierarchy" functionality.
The new Hierarchy window that you see shown below on the right provides supertype and subtype information, as opposed to the previous releases where this information was displayed in modal dialogs. Several small helpful related changes include integration with the Javadoc window, as can be seen below, which updates itself based on what is selected in the Navigator, Hierarchy window, or editor:
All in all, you'll have a cleaner user interface with all related information immediately and contextually available in the IDE's supporting windows.
Much more info here: