Probably the most obvious feature of a rich client application is the user interface, which determines the quality of an application based on an intuitive and user-friendly structure of functions and data. It can be a challenge to create a user interface with only a source code editor, however. Not only do you constantly have to imagine the structure of the components, but the result often looks completely different than expected.
In this respect the NetBeans IDE, which contains a powerful Swing GUI Builder, proves to be very innovative. You can create a whole user interface with drag-and-drop and a choice of given parameters. In other words, you do not need to write even a single line of code.