Everybody knows Ubuntu, right? And I bet that some of you heard about Openbox, the standards compliant, fast, lightweight, extensible window manager (similar to Fluxbox). Well, CrunchBang is a Linux distribution based on Ubuntu and powered by Openbox!

WattOS Beta 3 is a lightweight Linux Distro geared towards running on less energy and for recycled or low power computers without compromising on features or performance that you’d expect from a full power system. Their motto “Light, Fast, Now” seeks to provide a low-energy full featured Linux distro.

A lightweight Linux distribution often seems to require making sacrifices - using a UI which many users would find unfamiliar and using software which is heavily cut down in functionality.

Window Maker is a fast, lightweight window manager based as closely as possible on the look and feel of the NeXTStep interface. (You may be familiar with NeXTStep an ancestor of Mac OSX, although the look and feel has changed a fair bit between the two.)

Xfe (X File Explorer) is a wonderful, fast and lightweight file manager for Linux built using the FOX toolkit with a customisable interface which can resemble the twin-panel style of Midnight Commander if needed.

The Lubuntu project (Ubuntu based on LXDE) just published it's first ISO. LXDE is a very lightweight and minimal desktop environment using the openbox window manager, the PcManFM file manager, and a very select list of default applications.

Screenshots of the recently released WattOS R2 Linux distribution, known for being energy efficient and providing a lightning fast LXDE desktop.

An extremely fast and lightweight file manager for X.PCMan File Manager is a gtk2 based file manager for the X Window System.

JWM (Joe's Window Manager) is a very lightweight window manager for use with X windows under Linux or Unix. My compiled version weighs in at 138KBytes in size, not the dozens of megabytes like KDE or GNOME. If you are looking for a simple kiosk system interface or a lightweight desktop for a dedicated server, then JWM should fit the bill nicely.