Gnome vs Xfce

General

Both are Desktop Environments for the X Window System with their own Window Managers. Both are highly customizable (GTK).

Xfce is described as "[…]a lightweight desktop environment for various *NIX systems. Designed for productivity, it loads and executes applications fast, while conserving system resources."[1] Xfce also strongly supports the unix-thought of highly transparent software.

Gnome focuses on usability and support.

Performance

• Due to Xfce's low resource usage, it also runs on computers with slow graphic cards or with generic graphic card drivers (mesa) only.
• On Xfce, having no Hardware-Acceleration in use, windows move much faster when dragged around than on Gnome.

Usability

• Xfce equally supports KDE-, Qt-, GTK- and Xfce-Applications. Xfce even supports Gnome Applets (xfapplet-plugin)
• Gnome Desktop's office software is connected. E.g., you can see fixed dates in the Gnome Calendar (Clock) you typed into Gnome's office solution named Evolution before.

Tricks & Tipps

Gnome

• Use Xfce's window manager xfwm4 instead of Gnome's Metacity for faster window movement on Gnome with no hardware acceleration.

Xfce

• Xubuntu distributes a Xfce-Environment similar to Ubuntu (Gnome), so no further setups are needed.