CrunchBang Linux is based on Debian Squeeze and uses the Openbox Window manager, along with mainly GTK+ apps. It is extremely lightweight and fast, but also very customisable and usable. It includes out of the box support for Flash, DVDs and MP3s.
CrunchBang makes good use of shortcuts to commonly used applications, these can be seen in Conky on the right.
The main menu, accessible by right clicking on the desktop, is highly configurable, although it doesn't by default automatically update when new applications are installed. see here for more on the menu.
As already mentioned, Crunchbang uses the Openbox Window manager.
The panel is Tint2 which can also act as a desktop switcher, by default it shows task bars for both desktops and the applications open in each one; the desktop can be switched by clicking on the relevant taskbar section.
The desktop background is controlled by Nitrogen.
CrunchBang also comes with Conky System monitor installed by default.
CrunchBang comes with a selection of apps, as well as those mentioned above it includes: