[edit] Nevermind, found it. Seems to have been removed and brought back a few versions ago. Neither as useful nor as visually impressive as the Windows version though.

No I meant Xfce. I can't find that function. Are you refering to sorting by rules? I mean ordering windows by drag and drop. As far as I know no window manager or desktop environment allows that except the Windows desktop. It even does it in an very elegant way.

If I have VirtualBox open and a machine running I can drag both windows in the taskbar together and say, position them behind my browser.