What is Arch Linux?
Arch Linux is an independently developed i686/x86-64 community distribution, based on a rolling-release model and targeted at competent GNU/Linux users which offers large binary repositories and excellent package management as well as a ports-like packaging system. Development focuses on a balance of minimalism, elegance, code correctness and modernity. Version 0.1 (Homer) was released March 11, 2002.
Arch provides a minimal environment upon installation, (no GUI), compiled for i686/x86-64 architectures. Arch is lightweight, flexible, simple and aims to be very
UNIX-like. Its design philosophy and implementation make it easy to extend and mold into whatever kind of system you're building- from a minimalist console machine to the most grandiose and feature rich desktop environments available. Rather than tearing out unneeded and unwanted packages, Arch offers the power user the ability to build up from a minimal foundation without any defaults chosen for them. It is the user who decides what Arch Linux will be.
Unique Package Management
Arch is backed by an easy-to-use binary package system - pacman - that allows you to upgrade your entire system with one command. Pacman is coded in C and designed from the ground up to be lightweight, simple and very fast. Arch also provides a ports-like package build system (Arch Build System) to make it easy to build and install packages from source, which can also be synchronized with one command. You can even rebuild your entire system with one command. Everything is done quite simply and transparently. The rolling release model allows one-time installation and continuous seamless upgrades, without ever having to reinstall or perform elaborate system upgrades from one version to the next.
Arch Linux strives to maintain the latest stable version of its software, based on a rolling-release system. We currently support a streamlined core package set for the minimal i686 and x86-64 base systems, thousands of additional, high-quality binary packages among both developer and user maintained repositories, and many thousands of PKGBUILD scripts, for building and packaging from source. Arch provides non-patched, vanilla software; packages are offered from pure upstream sources, how the author originally intended it be distributed. Patching only occurs in extremely rare cases, to prevent severe breakage in the instance of version mismatches that may occur within a rolling release model. Arch incorporates many of the newer features available to GNU/Linux users, including modern filesystems (Ext2/3/4, Reiser, XFS, JFS), LVM2/EVMS, software RAID, udev support and initcpio, as well as the latest available kernels.
The Arch Way is a philosophy aimed at keeping it simple. The Arch Linux base system is quite simply the minimal, yet functional GNU/Linux environment; the Linux kernel, GNU toolchain, and a handful of optional, extra command line utilities like links and Vi. This clean and simple starting point provides a rock solid base for expanding the system into whatever the user requires.
Arch's simple init system is heavily inspired by the *BSD way of incorporating calls from a single file, (etc/rc.conf), rather than a convoluted directory structure containing dozens of symlinks for each runlevel.
System configuration is achieved through editing simple text files.
Arch's home page is at http://www.archlinux.org/ where you can also find links to the user forums, official documentation, and everything else that is Arch. You can also read The Arch Way for a bit more insight in case you missed it here.