Compiz Reloaded is a compositing window manager that uses 3D graphics acceleration via OpenGL. It provides various new graphical effects and features on any desktop environment, including Gnome and KDE. (Short version: Wobbly windows and stuff)
Compiz Reloaded is the Further development of Compiz 0.8.x series.
Compiz Fusion is the result of a merge between the well-known Beryl composite window manager and Compiz Extras, a community set of improvements to the Compiz composite window manager. Compiz Fusion aims to provide an easy and fun-to-use windowed environment, allowing use of the graphics hardware to
... [More] render each individual window and the entire screen, to provide some impressive effects, speed and usefulness. [Less]
Enlightenment is not just a window manager for Linux/X11 and others, but also a whole suite of libraries to help you create beautiful user interfaces with much less work than doing it the old fashioned way and fighting with traditional toolkits, not to mention a traditional window manager.
... [More] window manager is a lean, fast, modular and very extensible window manager for X11 and Linux. It is classed as a "desktop shell" providing the things you need to operate your desktop (or laptop), but is not a whole application suite. This covered launching applications, managing their windows and doing other system tasks like suspending, reboots, managing files etc. [Less]
Avant Window Navigator is a dock for the Free Desktop which shows your launchers and open applications. It also contains support for extensions, via plugins for third-party applications, which communicate with the dock with DBus, and via applets, which allows for workspace switchers, system trays
... [More], clocks, etc., to be embedded in the dock. These applets can be written in C, Vala, or Python.
Awn currently requires compositing support in order to run. Window managers which support compositing include (but are not limited to) Metacity (part of GNOME), Xfwm4 (part of Xfce), KWin (part of KDE4.x), and Compiz. There are also standalone compositing managers, for window managers without support built-in: Cairo Compositing Manager and xcompmgr. [Less]
Cairo Composite Manager is a versatile and extensible composite manager which use cairo for rendering. Rendering can be done in 2D or 3D, using Xrender and Glitz backends. Plugins can be used to add some cool effects to your desktop.