Enlightenment 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.
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. It covers uses from small mobile devices like phones all the way to powerful multi-core desktops (which are the primary development environment).
To install Enlightment window manager open a Terminal window (Applictions -> Accessories -> Terminal) and copy+paste the following lines:
sudo apt-get install e17
When installed Logout and Change Session (at the bottom of GDM login screen after you click on username). Select Enlighment and Log back into Ubuntu, when using Enlighment for the first time you need to answer some questions first. The language you want to use (English or Chinese) and a list will of applications will be shown where you can mark applications to create quick launchers for applications you can add to your panel.
When you answered these questions you are good to go but a lot of work needs to be done before the Enlightment desktop is setup and working.