Xubuntu is a derivative of Ubuntu Linux that uses the Xfce desktop environment for the user interface. It is one of the official derivatives of Ubuntu Linux. The intent is for Xubuntu to be easy to use while being attractive and light on system resources. From the Xubuntu Strategy Document:

The target audience for Xubuntu consists of users who are interested in having an elegant, easy to use, polished and unified operating system. Xubuntu is a good option for those who want a stable, configurable and/or relatively light desktop environment too. Finally, Xubuntu is an appealing choice for users who prefer conservative workflows over the newest innovations. Continue reading →