An Italian programmer called Andrea Cimitan proved that is possible to put transparency in GTK+ widgets. The transparency in the GTK+ widgets is possibly by the use of Murrine Engine, Murrine is a Gtk2 engine, written in C language, using Cairo vectorial drawing library to draw widgets. It features a modern glassy look, and it is elegant and clean on the eyes. It is also extremely customizable, by a application called Murrine Configurator.
Andrea is searching for coders to help in the Murrine Configurator, if you have some time and skills in PyGtk check you the Andrea blog.
