This project was just provisioned. You can see the proposal here.
WindowBuilder is composed of SWT Designer and Swing Designer and makes it very easy to create Java GUI applications without spending a lot of time writing code. Use the WYSIWYG visual designer and layout tools to create simple forms to complex windows; the Java code will be generated for you. Easily add controls using drag-and-drop, add event handlers to your controls, change various properties of controls using a property editor, internationalize your app and much more.
WindowBuilder is built as a plug-in to Eclipse and the various Eclipse-based IDEs (RAD, RSA, MyEclipse, JBuilder, etc.). The plug-in builds an abstract syntax tree (AST) to navigate the source code and uses GEF to display and manage the visual presentation.
Generated code doesn't require any additional custom libraries to compile and run: all of the generated code can be used without having WindowBuilder Pro installed. WindowBuilder Pro can read and write almost any format and reverse-engineer most hand-written Java GUI code. It also supports free-form code editing (make changes anywhere...not just in special areas) and most user re-factorings (you can move, rename and subdivide methods without a problem).
Welcome to the new WindowBuilder homepage! We are thrilled to see WindowBuilder emerge as a new open source project, and we are excited to work with the Eclipse community to grow and evolve the tool.
We are in the process of getting the initial code contributions into Eclipse and into the IP review process. In the meantime, if you are interested in the project, you can see the current docs for the project at code.google.com.