Xfce

Xfce is a lightweight desktop environment for various *NIX systems. Designed for productivity, it loads and executes applications fast, while conserving system resources."

Installing Xfce 4 on Fedora

yum -y groupinstall XFCE && yum -y install switchdesk

or

yum -y install xfce4-session xfdesktop Thunar xfce-utils libxfce4util libxfce4mcs xfce4-session-engines \
libxfcegui4 xfce4-panel xfwm4 xfce4-mixer xfce4-icon-theme xfce4-appfinder switchdesk.noarch

To switch from your current Desktop Environment to XFCE, use switchdesk

switchdesk-helper
Please specify one of either KDE, GNOME, XFCE, FVWM or WindowMaker.
switchdesk XFCE

To start and run Xfce run

startxfce4

For more info see: http://fedoranews.org/blog/?p=628, http://fedoranews.org/contributors/diego_figueroa/xfce/