Note
This page is only applicable to people using X.org 6.8.0-ast14 or higher.
Warning
Due to the licensing changes made by some of the XFree86 developers, the patches and prepatched tarballs will no longer be distributed for XFree86 versions. I find it very hard to believe there are many people who are still using XFree86 now anyway.
Note
Work on the X.org based system is progressing, albeit too slowly. Current information can be found here.
Since the release of X.org v6.8.0-ast14 there has been support for full transparency and is capable of supporting drop shadows. By default full transparency is disabled, because of the problems it can cause with an overlapping window's content visually "clashing". And due to the user interface problems that can happen with full transparency enabled this page has been written, and the screenshots taken, without full transparency enabled.
The above image is from Enlightenment. The most obvious effect of enabling drop shadows is the heightened sense of depth with the windows.
Warning
It is generally not a good idea to enable either drop shadows or full transparency support if you running X over the network or if you don't have the MIT-SHM extension loaded. Updating and rendering will take excessively long, or will not work correctly at all. This doesn't affect releases after v4.3.0-ast21, as the features automatically disable in such circumstances.
A perhaps more impressive example of using drop shadows is below, it features the XFce4 desktop system.
To enable drop shadow support you can either use gxset configuration tool to change the settings of a live system, or for more fine-grained and static control over the display you can directly edit your /etc/X11/xorg.conf:
# Add "drop_shad" to the Module section, for example:
Section "Module"
Load "dbe"
Load "dri"
Load "drop_shad"
Load "extmod"
Load "glx"
Load "record"
Load "xtrap"
Load "speedo"
Load "type1"
Load "freetype-x"
EndSection
# Then add a "drop_shad" section, for example:
Section "drop_shad"
Option "Enabled" "On"
# The next option chooses sharp or filtered shadows
Option "Sharp" "Off"
Option "XDepth" "8"
Option "YDepth" "8"
# The option "colour" can be referenced as "color"
Option "Colour" "black"
# Shadow opacity as a percentage
Option "Opacity" "80"
EndSection