Xfce (pronounced as four individual letters) is a free software desktop environment for Unix and other Unix-like platforms, such as Linux, Solaris, and BSD. It aims to be fast and lightweight, while still being visually appealing and easy to use.
The current version, 4.8, is modular and reusable. It consists of separately packaged components that together provide the full functionality of the desktop environment, but which can be selected in subsets to create the user's preferred personal working environment. Xfce is mainly used for its ability to run a modern desktop environment on relatively modest hardware.
It is based on the GTK+ 2 toolkit (the same as GNOME). It uses the Xfwm window manager. Its configuration is entirely mouse-driven, and the configuration files are hidden from the casual user.
Xfce is included as one of the Graphical User Interfaces on the Pandora handheld gaming system. It is possible to run Xfce with 40MB of memory using Alpine Linux.Reference used: Wikipedia