That's the UI editor of the already since ~3 years dead and abandoned Woodstock library. That library became an epic failure due to an bug which revealed when Firefox 3 was released. It turned out that the library generates non-standards compliant Javascript which broke in the newer and more standards-compliant browsers. It was a hard smack in Woodstock's face.
Since then, users were recommended to migrate to IceFaces or RichFaces. There's an auto-migration tool for iceFaces. IceFaces in turn has a visual editor plugin for Netbeans (check Tools Support links).
Another fact is, using visual editors with code generators is strongly discouraged in the professional development world. They were often used by starters only and it produces unmaintainable and unreuseable code to a high degree. On the other hand, it makes debugging and nailing down code-level problems much harder for starters, because they don't understand any line of the generated code. It also unnecessarily gave JSF in general a negative imago.
If you're new, don't drag'n'drop code, but just write code.
If you like to develop JSF on Netbeans, I recommend walking through the latest tutorials at Netbeans.org instead. You can find them all here. With regard to JSF 2.0 in general, I can recommend the tutorials at Coreservlets.com and the book JSF 2.0: The Complete Reference as well.
