Debian is a free Linux distribution with thousands of contributors from all over the world. It serves as the basis for a number of other distributions, most notably Ubuntu and Knoppix. Debian's main software repositories are Free Software, conforming to the Debian Free Software Guidelines. Many architectures are supported, including x86, AMD64, PowerPC, SPARC, ARM, etc. The latest version, code-named lenny, was released on September 5, 2009.
Debian was created by Ian Murdock in 1993. The actual name of the project comes from the names of the creator of Debian, Ian Murdock, and his wife, Debra.[1]
The Debian Social Contract, a document describing the moral guidelines followed by the Debian project, was first published in July 1997.
Software in Debian, like in most Linux distributions, is installed in the form of packages. Debian's package management system is called dpkg. It has several front-ends: apt for command-line usage, the newer aptitude with a ncurses-based interface, and Synaptic - a GTK+ user interface. The main role of the package manager is to download and install packages, automatically resolving dependencies and running pre-install/post-install scripts.
Packages are available from several repositories. For the stable version of Debian, the official packages are in stable/main with security updates in stable/updates. There is also stable/non-free for packages that do not conform to the Debian Free Software Guidelines.
The Debian project does not have a regular release schedule, opting instead to release "when it's ready" (emphasizing quality instead of a strict deadline). Stable versions are released, on average, once every two years.
The project maintains several inter-related distributions: stable is the current, official version, and receives security updates. When a new version is released, the old version becomes oldstable and continues to receive security updates for a set period of time (currently 18 months). Developers upload new packages into the unstable distribution which, therefore, contains the latest versions of packages. These are automatically moved to testing once they meet certain criteria. Periodically, it is frozen and becomes the next stable version. There is also an experimental distribution, for packages that are not meant to reach the next release.
Codenames for releases are inspired by the names of characters from the Pixar/Disney movie Toy Story. The current release (5.0) is named lenny. Previous stable releases have been named buzz (1.1), rex (1.2), bo (1.3), hamm (2.0), slink (2.1), potato (2.2), woody (3.0), sarge (3.1) and etch (4.0). The current "testing" version, which will become the next stable release, is named squeeze. The "unstable" version is always known as sid - after the boy next door that likes to break toys for fun.