A GTK+ interface for the opensuse's YaST setup tool. I have developed it as a Google Summer of Code project, mentored by Michael Meeks. It got adopted as the default YaST in Gnome and XFCE desktops ever since openSUSE 10.3, as well as for the SLED and SLES line of corporate products.
Maps the GTK style on Qt applications, making KDE/Qt look (and partially behave) as GTK applications.
Sadly there wasn't much interest on this at the time, so the project stalled. However Nokia has since started an identical project called QGtkStyle.
As part of 2007 Google's Summer of Code, I developed an initial implementation of a layout framework that used logical positioning (boxes, tables, ...) to place the UI elements rather than absolute coordinates. As part of the project, I also developed a XML format to more easily create the UI, and an editor to go with it.