The UDE-Project is creating a new WM which will be a complete GUI in future. The project does not use any special GUI-Libraries such as QT or GTK+. We just use the standard Xlibs (both to keep UDE fast and slim and to avoid dependencies). UDE has a completely original Look'n'Feel, it's not just another copy of the so well known "classical" window management user interface.
UDE - Get used to it!