I recently noticed that although I have already talked about using KDE4's KWin in KDE3 or any other window manager in KDE instead of KWin, there is one thing missing in the mix: Using KWin without the KDE desktop.
Yes, perfectly possible. KWin is actually a KDE application like any other (well, more or less) and so just like other KDE applications it can run in GNOME, Xfce or even standalone, as long as the KDE libraries are available. And while some people may wonder about the sense of this, some apparently see it.
So, let's have a look at how to use KWin in GNOME, Xfce or standalone. As the title suggests, there will be some resistance, but that can be overcome Eye-wink.
KWin standalone: Let's start with the simplest case. And also probably the least likely. It is possible to use KWin alone without any desktop, just like it is possible to use for example WindowMaker or FVWM. However, unlike those, KWin is not very suited for this task, as it is a pure window manager. Meaning, it provides only window management features and not additional elements of the desktop like the taskbar, desktop background or application launching. So while such usage is possible, I don't expect many people would try it, without additional tools to provide other desktop functionality. If you try it, it's simple - just launch KWin, that's it.
rest here