Description: http://www.archlinux.org/about/
Quite out-of-date; still talks about [i]current[/i] and [i]release[/i], etc.

Here is an updated version:

About Arch Linux

Arch Linux is an independently developed, i686/x86-64 general purpose GNU/Linux distribution versatile enough to be molded to fit any role. Development focuses on simplicity, minimalism, modernity and code elegance. Arch is installed as a minimal base system, configured by the user and upon which their own ideal environment is assembled by installing only exactly what is required or desired for their own unique purposes. GUI configuration utilities are not provided, as system configuration is performed from the shell by editing simple text files. Arch strives to stay fairly bleeding edge, and typically offers the latest stable versions of software.

Arch Linux uses its own Pacman package manager, which couples a simple binary package format with an easy-to-use package build system, allowing users to easily manage and customize their packages, whether they be official Arch software, or the user's own custom built packages from 3rd party sources. The repository system also allows users to build and maintain their own custom build scripts, packages, and repositories, which encourages community growth and contribution.

The minimal Arch base system package set resides in the streamlined [core] repo. In addition, there exist the official [extra], [community], and [testing] repos, providing many thousands of high-quality, vanilla packages to meet your software demands. Arch also offers an [unsupported] branch in the Arch User Repository, which contains over 9,000 build scripts, for compiling from sources and subsequently easily creating installable packages with the Arch Build System's makepkg tool.

Arch Linux uses a "rolling release" system which allows one-time installation and perpetual software upgrades. Neither reinstallation nor upgrading from one "version" to the next is ever necessary. By issuing one command, the Arch system is kept up-to-date and on the bleeding edge.

Arch does not patch its software except in very rare cases and only to avoid severe breakage due to upstream version mismatches which may infrequently occur within the rolling release model.

If you share this vision of what a GNU/Linux distribution should be, then you are welcomed and encouraged to use it freely, get involved, and contribute to the community. Welcome to Arch!