DesktopX is a program that adds all kinds of features to your Windows desktop. And it would take way too long to list down all the incredible things it can do. So in a nutshell it does 3 things:
1) You can put mini-applications called "Widgets" on your desktop. Think of widgets as being tiny desktop level utilities that don't have the overhead of a standa lone program. And better yet, these widgets can be irregularly shaped and support alpha blended edges. Windows Media Player could be a DesktopX widget (for instance). Well, except if it were a DestopX widget it could support shadows and alpha blended (no jaggies) on its edges. 
Example of DesktopX widgets: Screenshot
2) You can have what amounts to animated icons on your desktop via DesktopX objects. So when you put your mouse over them, they can animate or they might walk back and forth around your desktop. Or they might play a sound or spin around or do all kinds of other things.
Example of DesktopX objects in action: Screenshot, Video
3) Building entire desktops. This is where you combine the power of DesktopX objects and widgets to build a whole new shell environment for Windows.
Example of a DesktopX theme in action: Screenshot
There are 3 sections for DesktopX here on WinCustomize. One for objects, one for widgets, and one for themes.
If you've tried DesktopX in the past but don't use it now, try out this new version, it's a whole new ballgame.
Stardock's new game, The Political Machine, was developed in part with DesktopX 2.2 (this is the game that was featured in Time Magazine last week). DesktopX has also been seen in various movies providing those fake computer screens.
DesktopX is part of Stardock's Object Desktop suite of Windows extension utilities. Object Desktop includes WindowBlinds, ObjectBar, IconPackager, Keyboard LaunchPad, IconDeveloper, SkinStudio, DesktopX, and much more.
You can also get DesktopX on its own at http://www.desktopx.net.
See full list of changes here.