Evolved into Sun Forté then to One Studio, then to Sun Studio. Download is 15 MB vs 85 MB for One Studio. Has an absolute layout manager that they automatically convert to GridBagLayout. So you do your tweaking in the absolute layout manager and then do the conversion. I found the GUI builder quite buggy, though nicely designed. It would let you add any kind of component. It built event handling code. You could cut and paste components. It handled many kinds of layout. The lastest version is reputed to be remarkably quick.

NetBeans is an open-source integrated development environment (IDE) written entirely in Java. Sun ONE Studio (formerly called Forte for Java) is based on this.

NetBeans is a cross platform Java IDE which is now a product of Sun Microsystems following their acquisition of Czech based NetBeans in October 1999. Together with Sun's acquisition of Forte, it will extend the JDK: NetBeans is the core of Forte for Java, Community Edition, Sun Microsystems' first open source development tool and successor to Java Workshop.