Property editor. a table list with autogenerated editors for whatever object you put in it.
JModalWindow supports modal functionality, similar to JDialog, without blocking all frames.
SwingSet open source Java toolkit that allows the standard Java Swing components to be made database-aware.
JCustomizer generic and persistent customization of every Java Swing/AWT GUI at runtime: fonts, colors, texts, accelerators, ... A nice accompaniment is a WYSIWYG access to internationalization without programming efforts.
JPrintPreview print preview dialog for any Java application
PSwing Components combo box, date picker, color picker, font picker, and integer text field.
Float API provides multiple floating-Window JPanels which can be docked in other JPanels.
Animated Label - version of JLabel suitable for simple animations