Xfce

Xfce (pronounced as four individual letters) is a free software desktop environment for Unix and 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. 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.