There are many Window Managers available for Linux including the two most popular KDE and GNOME, as well many older ones. Enlightenment has been around for a while, but that doesn't mean it's outdated. It's lightweight, flexible, and reliable. It does its job well and doesn't try to do things it shouldn't. And it can look really, really good.
Before we discuss Enlightenment, let's break apart the Window Manager/Desktop Environment issue: which does what; what are they; why do we need them?
On top of the base of the Linux system, you have the X Window System. This system is a portable, network-transparent system that, by itself, can't do much. If you were to start up the X Windows System (with the command X), you would see a nice grey screen with a big X cursor. That big X cursor can move around, but that's it; you can't click anything or open anything. But X is critical: It is the underlying framework that allows the Window Manager to do its thing.
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