CrunchBang Linux (often referred to simply as "#!" because of its logo) is a lightweight Ubuntu based Linux distribution created by Philip Newborough. It uses the Openbox window manager and is especially suitable for low-end hardware with limited resources (e.g. the ASUS Eee PC).[2] It is provided as an installable Live CD.

CrunchBang Linux is designed to offer a good balance of speed and functionality. It has been reported to boot faster than Ubuntu by Softpedia, but also includes a larger number of applications by default than a standard Ubuntu installation. It operates better under low resources than Ubuntu and is faster than a normal Ubuntu distribution. CrunchBang Linux has been developed completely from Ubuntu sources with the exception of few packages.

Unlike Ubuntu, CrunchBang includes several non-free or patent encumbered applications and libraries such as out-of-the-box support for several multimedia formats including MP3, Adobe Flash as well as DVD playback. CrunchBang also replaces some applications that are included with default Ubuntu, such as:
* Openbox Window Manager instead of the GNOME Desktop Environment
* ROX-Filer and Thunar (replaced by PCMan File Manager in CrunchBang 8.10.02) are used as file managers instead of Nautilus
* AbiWord and other GNOME Office components instead of OpenOffice.org
* Deluge BitTorrent client in place of Transmission
* Skype VoIP client instead of Ekiga
* CrunchBang also uses a different GTK theme, icon set and default wallpapers.