slackbuilds_ponce/desktop/cairo-compmgr

cairo-compmgr (Drop-in replacement for xcompmgr)

This composite manager uses the cairo library to provide similar
effects to xcompmgr.  You can use it with any window manager, such
as fluxbox, to provide transparencies.  xcompmgr was designed as an
example program and cairo-compmgr is designed as an actual standalone
composite manager.

Warning: this plays a bit weird with fluxbox.  Tabs of grouped
windows will be drawn under windows if cycling through with alt+tab.
Additionally when a sub sub root menu loops back over it self, it
will be drawn under the other menus.  Other than that, it's an added
improvement in visual effects over xcompmgr.

libgtop is an optional dependency.