Pacman 3.0.4

Pacman project is a simple library-based package manager for Linux.

Pacman is a utility which manages software packages in Linux. It uses simple compressed files as a package format, and maintains a text-based package database (more of a hierarchy), just in case some hand tweaking is necessary.

Pacman does not strive to "do everything." It will add, remove and upgrade packages in the system, and it will allow you to query the package database for installed packages, files and owners. It also attempts to handle dependencies automatically and can download packages from a remote server.

Although the package manager itself is quite simple, the Pacman tarball also comes with scripts that help automate building and installing packages. These are used extensively in the Arch Build System (ABS), used in Arch Linux.
As of version 2.0, Pacman can also keep your systems packages in sync with a master server. You can follow CURRENT and STABLE trees, or lock yourself into a specific version. See the Pacman manpage for more info on this (--sync operation).

As of version 3.0, Pacman has been lib-ified, with a backend library named libalpm (Arch Linux Package Management). Speed in some cases has been improved, and this should allow us in the future to speed development of alternative front ends.