Enlightenment is a
window manager for the
X Window System. Though it is a window manager, Enlightenment (often simply referred to as "E") is generally considered more complex than most window managers, while remaining fairly fast and efficient. It is sometimes used on low-end systems, where
RAM and
CPU time are at a premium, rather than a full
desktop environment. Its use is not, however, limited to such systems, and it is often used in conjunction with -- or by people that do not want -- a full desktop environment such as
KDE or
GNOME, even on fast systems.
The next major version, currently in development and known as E17 (the current "stable" version at time of writing is 16.5), is designed to be a desktop shell[?]; somewhere between a window manager and a desktop environment.