Well, not totally sure... I think I just took the defaults when I orginally installed the OS...
Maybe it is IceWM... I am sorry, I am used to using GNOME, KDE or Fluxbox... I can tell you it is not any of those.
Is there away to tell?
It has a start button (IE Like windoze)... but it says "MENU" . I believe it is IceWM, but again, not totally sure.