It might seem as if one needs a whole desktop environment in order to enjoy the luxury of compositing and its so called real transparency, but in fact this is not the case.
All one needs is to have X compiled with composite support (
USE="xcomposite" in Gentoo) and two small X applications (both are in the official Portage tree):
- xcompmgr – a lightweight compositing manager
- transset-df – an application with which one can select the desired transparency levels (this is a patched/improved version of the original X.org's transset)
xcompmgr does not have all the nifty effects as KDE or GNOME or Compiz do, it does pack real transparent windows (as well as panels etc.), basic shadows and a few more tricks.
man pages of these two are short and quite self-explenatory, so I find it obsolete to describe the usage here.