Ribs - ReportMill's Interface Builder for Swing
- Offers a GUI updating modell, one point of entry response handling and a springs and struts absolute positioned layout. The site informs on features, offers documentation, and a WebStart demo. [Commmercial]
- http://www.reportmill.com/ribs/

JAXFront
- A XML schema based GUI rendering engine generates presentation GUIs "on-the-fly", using an XML schema based representation of the business model. It offers a powerful Visual Editor (XUI-Editor) for adjusting or completely redesign GUI and Forms
- http://www.jaxfront.org/

Simplicity for Java
- Java GUI development environment for any Java-enabled platform. Professional version includes database integration, servlet development, and cross-platform testing. [Commercial]
- http://www.datarepresentations.com/

Abeille Forms Designer
- A GUI builder for Java applications. Developers and designers can create complex, professional forms. Designers can drop and drop components onto a WYSIWYG editor. [Open source, LGPL]
- https://abeille.dev.java.net/

ThinCLet
- An add-on for Thinlet, the lightweight GUI toolkit for Java. ThinCLet assist to componentize Thinlet applications. It is written by Koen Roevens. [Open source, LGPL]
- http://thinclet.sourceforge.net/

JFrameBuilder
- Enables Java developers to create GUI applications using drag-and-drop interface. [Commercial]
- http://www.mars3000.com

Adaptable Layout Environment (ALE)
- Allows laying out components in a program via a configuration file rather than hard-coding using a layout manager.
- http://locutus.kingwoodcable.com/jfd/java/ale/ale.html

GridBagger
- A visual editor for creating GUI's with Java's GridBagLayout class. [Freeware]
- http://www.cellspark.com/GridBagger.html

SpeedJG
- A GUI builder tool to create state-of-the-art Java Swing applications. The meta data that describe the GUI are mapped to XML from where Components can be created on the fly or Java source code is generated. [Commercial]
- http://www.wsoftware.de/SpeedJG/

jvider
- A GUI builder tool for Java Swing applications. [Shareware]
- http://jvider.com/