Debian

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Debian is a computer operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...

 composed of software packages released as free and open source software
Free and open source software
Free and open-source software or free/libre/open-source software is software that is liberally licensed to grant users the right to use, study, change, and improve its design through the availability of its source code...

 primarily under the GNU General Public License
GNU General Public License
The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....

 along with other free software
Free software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...

 licenses. Debian GNU/Linux, which includes the GNU
GNU
GNU is a Unix-like computer operating system developed by the GNU project, ultimately aiming to be a "complete Unix-compatible software system"...

 OS tools and Linux kernel
Linux kernel
The Linux kernel is an operating system kernel used by the Linux family of Unix-like operating systems. It is one of the most prominent examples of free and open source software....

, is a popular and influential Linux distribution
Linux distribution
A Linux distribution is a member of the family of Unix-like operating systems built on top of the Linux kernel. Such distributions are operating systems including a large collection of software applications such as word processors, spreadsheets, media players, and database applications...

. It is distributed with access to repositories containing thousands of software packages ready for installation and use. Debian is known for relatively strict adherence to the Unix
Unix philosophy
The Unix philosophy is a set of cultural norms and philosophical approaches to developing software based on the experience of leading developers of the Unix operating system.-McIlroy: A Quarter Century of Unix:...

 and free software
Free software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...

 philosophies as well as using collaborative software development and testing processes. Debian can be used on a variety of hardware, from NAS devices to phones, laptops, desktops and servers. It focuses on stability and security and is used as a base for many other distributions.

Organization


The Debian Project is governed by the Debian Constitution and the Social Contract which set out the governance structure of the project as well as explicitly stating that the goal of the project is the development of a free operating system. Debian is developed by over three thousand volunteers from around the world and supported by donations through several nonprofit organization
Nonprofit organization
Nonprofit organization is neither a legal nor technical definition but generally refers to an organization that uses surplus revenues to achieve its goals, rather than distributing them as profit or dividends...

s around the world. Most important of these is Software in the Public Interest
Software in the Public Interest
Software in the Public Interest, Inc. is a non-profit organization formed to help other organizations create and distribute free/open-source software and open-source hardware...

, the owner of the Debian trademark and umbrella organization
Umbrella organization
An umbrella organization is an association of institutions, who work together formally to coordinate activities or pool resources. In business, political, or other environments, one group, the umbrella organization, provides resources and often an identity to the smaller organizations...

 for various other community free software projects.

Thus, the Debian Project is an independent decentralized organization; it is not backed by a company like Linux distributions such as Ubuntu
Ubuntu (operating system)
Ubuntu is a computer operating system based on the Debian Linux distribution and distributed as free and open source software. It is named after the Southern African philosophy of Ubuntu...

, openSUSE
OpenSUSE
openSUSE is a general purpose operating system built on top of the Linux kernel, developed by the community-supported openSUSE Project and sponsored by SUSE...

, Fedora
Fedora (operating system)
Fedora is a RPM-based, general purpose collection of software, including an operating system based on the Linux kernel, developed by the community-supported Fedora Project and sponsored by Red Hat...

, and Mandriva
Mandriva Linux
Mandriva Linux is a Linux distribution distributed by Mandriva. It uses the RPM Package Manager...

. The cost of developing all the packages included in Debian 5.0 lenny (323 million lines of code), using the COCOMO
COCOMO
**********************************************************************************************The Constructive Cost Model is an algorithmic software cost estimation model developed by Barry W. Boehm...

 model, has been estimated to be about US$
United States dollar
The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....

 8 billion. Ohloh
Ohloh
Ohloh is a website which provides a web services suite and online community platform that aims to map the landscape of open source software development. It was founded by former Microsoft managers Jason Allen and Scott Collison in 2004 and joined by the developer Robin Luckey...

 estimates that the codebase (54 million lines of code), using the COCOMO
COCOMO
**********************************************************************************************The Constructive Cost Model is an algorithmic software cost estimation model developed by Barry W. Boehm...

 model, would cost about US$
United States dollar
The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....

 1 billion to develop.

Features


Debian is known for an abundance of options. The current stable release includes over twenty nine thousand software packages
Software package (installation)
In package management systems, which are commonly used with Linux-based operating systems, a package is a specific piece of software which the system can install and uninstall....

 for nine computer architecture
Computer architecture
In computer science and engineering, computer architecture is the practical art of selecting and interconnecting hardware components to create computers that meet functional, performance and cost goals and the formal modelling of those systems....

s using the Linux kernel and two also using the FreeBSD
FreeBSD
FreeBSD is a free Unix-like operating system descended from AT&T UNIX via BSD UNIX. Although for legal reasons FreeBSD cannot be called “UNIX”, as the direct descendant of BSD UNIX , FreeBSD’s internals and system APIs are UNIX-compliant...

 kernel (kfreebsd-i386 and kfreebsd-amd64). These architectures range from the Intel/AMD 32-bit/64-bit
X86-64
x86-64 is an extension of the x86 instruction set. It supports vastly larger virtual and physical address spaces than are possible on x86, thereby allowing programmers to conveniently work with much larger data sets. x86-64 also provides 64-bit general purpose registers and numerous other...

 architectures commonly found in personal computer
Personal computer
A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...

s to the ARM architecture
ARM architecture
ARM is a 32-bit reduced instruction set computer instruction set architecture developed by ARM Holdings. It was named the Advanced RISC Machine, and before that, the Acorn RISC Machine. The ARM architecture is the most widely used 32-bit ISA in numbers produced...

 commonly found in embedded system
Embedded system
An embedded system is a computer system designed for specific control functions within a larger system. often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal...

s and the IBM eServer zSeries mainframes
Mainframe computer
Mainframes are powerful computers used primarily by corporate and governmental organizations for critical applications, bulk data processing such as census, industry and consumer statistics, enterprise resource planning, and financial transaction processing.The term originally referred to the...

. The Debian standard install makes use of the GNOME
GNOME
GNOME is a desktop environment and graphical user interface that runs on top of a computer operating system. It is composed entirely of free and open source software...

 desktop environment. It includes popular programs such as OpenOffice.org
OpenOffice.org
OpenOffice.org, commonly known as OOo or OpenOffice, is an open-source application suite whose main components are for word processing, spreadsheets, presentations, graphics, and databases. OpenOffice is available for a number of different computer operating systems, is distributed as free software...

, Iceweasel (a rebranding
Rebranding
Rebranding is the creation of a new name, term, symbol, design, or a combination of them for an established brand with the intention of developing a differentiated position in the mind of stakeholders and competitors....

 of Firefox), Evolution mail, CD/DVD writing programs, music and video players, image viewers and editors, and PDF
Portable Document Format
Portable Document Format is an open standard for document exchange. This file format, created by Adobe Systems in 1993, is used for representing documents in a manner independent of application software, hardware, and operating systems....

 viewers. There are pre-built CD images for KDE Software Compilation
KDE Software Compilation
The KDE Software Compilation is a desktop environment and an associated range of KDE Applications produced by KDE. Prior to version 4.4, released in February 2010, the Software Compilation was known as KDE, which used to stand for K Desktop Environment until November 2009...

, Xfce
Xfce
Xfce is a free software desktop environment for Unix and other Unix-like platforms, such as Linux, Solaris, and BSD – though recent compatibility issues have arisen with regard to BSD Unix platforms...

 and LXDE
LXDE
LXDE is a free and open source desktop environment for Unix and other POSIX compliant platforms, such as Linux or BSD. The goal of the project is to provide a desktop environment that is fast and energy efficient...

 as well. The remaining discs, which span five DVDs or over thirty CDs, contain all packages currently available and are not necessary for a standard install. Another install method is via a net install CD which is much smaller than a normal install CD/DVD. It contains only the bare essentials needed to start the installer and downloads the packages selected during installation via APT
Advanced Packaging Tool
The Advanced Packaging Tool, or APT, is a free user interface that works with core libraries to handle the installation and removal of software on the Debian GNU/Linux distribution and its variants...

. These CD/DVD images can be freely obtained by web download, BitTorrent, jigdo
Jigdo
Jigdo is a download utility initially designed around the Debian distribution of GNU/Linux that downloads files from several mirrors in order to build an optical disk image. Jigdo is free software, released under the GNU General Public License...

 or buying them from online retailers.

Package management


Debian was one of the first Linux distributions to compose itself from packages, and robust package management is perhaps Debian's most prominent feature. The APT
Advanced Packaging Tool
The Advanced Packaging Tool, or APT, is a free user interface that works with core libraries to handle the installation and removal of software on the Debian GNU/Linux distribution and its variants...

 package management system
Package management system
In software, a package management system, also called package manager, is a collection of software tools to automate the process of installing, upgrading, configuring, and removing software packages for a computer's operating system in a consistent manner...

, repositories with large numbers of packages, and strict policies regarding packages, promote high releases quality, easy upgrades between releases, and automated installation and removal of packages.

dpkg, installing local .deb packages


dpkg
Dpkg
dpkg is the software at the base of the Debian package management system. dpkg is used to install, remove, and provide information about .deb packages....

 is the base of the Debian package management system. dpkg
Dpkg
dpkg is the software at the base of the Debian package management system. dpkg is used to install, remove, and provide information about .deb packages....

 is a command-line utility to install, remove, and provide information about local .deb packages. GDebi
Gdebi
GDebi is a tool that can install .deb packages. It is available with a graphical interface, but also has a command line option. It is updated by using Update Manager....

 is a tool that expands the functionality of dpkg
Dpkg
dpkg is the software at the base of the Debian package management system. dpkg is used to install, remove, and provide information about .deb packages....

 by not only installing local .deb packages but also fetching and installing dependencies from online repositories. GDebi
Gdebi
GDebi is a tool that can install .deb packages. It is available with a graphical interface, but also has a command line option. It is updated by using Update Manager....

 can be used both in a graphical interface and by command-line.

APT, installing packages from online repositories


APT
Advanced Packaging Tool
The Advanced Packaging Tool, or APT, is a free user interface that works with core libraries to handle the installation and removal of software on the Debian GNU/Linux distribution and its variants...

 expands the functionality of dpkg
Dpkg
dpkg is the software at the base of the Debian package management system. dpkg is used to install, remove, and provide information about .deb packages....

 by searching, fetching and installing packages from online repositories along with their dependencies, either from binary files or by compiling source code. It can also upgrade packages and upgrade the whole distribution to a new release.

Graphical front-ends
  • Software Center
    Ubuntu Software Center
    Ubuntu Software Center is a computer program for browsing, installing and removing software on the Ubuntu operating system. Based upon the GNOME application, gnome-app-install, which is similar in function and appearance, it serves as a GTK+ graphical user interface front-end to the Advanced...

    , originally developed for Ubuntu
    Ubuntu (operating system)
    Ubuntu is a computer operating system based on the Debian Linux distribution and distributed as free and open source software. It is named after the Southern African philosophy of Ubuntu...

    , is a GNOME
    GNOME
    GNOME is a desktop environment and graphical user interface that runs on top of a computer operating system. It is composed entirely of free and open source software...

     program to discover and install applications.
  • Synaptic is a GTK+
    GTK+
    GTK+ is a cross-platform widget toolkit for creating graphical user interfaces. It is licensed under the terms of the GNU LGPL, allowing both free and proprietary software to use it. It is one of the most popular toolkits for the X Window System, along with Qt.The name GTK+ originates from GTK;...

     front-end for APT
    Advanced Packaging Tool
    The Advanced Packaging Tool, or APT, is a free user interface that works with core libraries to handle the installation and removal of software on the Debian GNU/Linux distribution and its variants...

    .
  • KPackage
    KPackage
    KPackage was KDE's package manager frontend.It supported BSD, Debian, Gentoo, RPM and Slackware packages. It provided a GUI for the management and upgrade of existing packages and the installation and acquirement of new packages...

     is KDE
    KDE
    KDE is an international free software community producing an integrated set of cross-platform applications designed to run on Linux, FreeBSD, Microsoft Windows, Solaris and Mac OS X systems...

    's front-end for APT
    Advanced Packaging Tool
    The Advanced Packaging Tool, or APT, is a free user interface that works with core libraries to handle the installation and removal of software on the Debian GNU/Linux distribution and its variants...

    .
  • Adept is a discontinued KDE
    KDE
    KDE is an international free software community producing an integrated set of cross-platform applications designed to run on Linux, FreeBSD, Microsoft Windows, Solaris and Mac OS X systems...

     front-end for APT
    Advanced Packaging Tool
    The Advanced Packaging Tool, or APT, is a free user interface that works with core libraries to handle the installation and removal of software on the Debian GNU/Linux distribution and its variants...

    .
  • Gnome Application Installer was a GNOME
    GNOME
    GNOME is a desktop environment and graphical user interface that runs on top of a computer operating system. It is composed entirely of free and open source software...

     program to discover and install applications, now removed in favour of Software Center
    Ubuntu Software Center
    Ubuntu Software Center is a computer program for browsing, installing and removing software on the Ubuntu operating system. Based upon the GNOME application, gnome-app-install, which is similar in function and appearance, it serves as a GTK+ graphical user interface front-end to the Advanced...


Command-line front-ends
  • apt-get
    Advanced Packaging Tool
    The Advanced Packaging Tool, or APT, is a free user interface that works with core libraries to handle the installation and removal of software on the Debian GNU/Linux distribution and its variants...

     is the most basic package management tool and the preferred APT
    Advanced Packaging Tool
    The Advanced Packaging Tool, or APT, is a free user interface that works with core libraries to handle the installation and removal of software on the Debian GNU/Linux distribution and its variants...

     front-end for non-interactive package management. It offers a command line user interface and it is most suitable for upgrades between major releases.
  • aptitude is the most versatile package management tool and the preferred APT
    Advanced Packaging Tool
    The Advanced Packaging Tool, or APT, is a free user interface that works with core libraries to handle the installation and removal of software on the Debian GNU/Linux distribution and its variants...

     front-end for interactive package management. It offers a full screen interactive text user interface, an enhanced package resolver and an enhanced search function. It is most suitable for the daily package management.
  • dselect
    Dselect
    dselect is a computer program used to manage software packages in the Debian operating system.dselect is one of the oldest front-ends to dpkg, and the bulk of its development happened when it was originally written by Ian Jackson, who wrote it alongside dpkg....

     is an old front-end for APT
    Advanced Packaging Tool
    The Advanced Packaging Tool, or APT, is a free user interface that works with core libraries to handle the installation and removal of software on the Debian GNU/Linux distribution and its variants...

    , largely superseded by other front-ends.
  • wajig
    Wajig
    Wajig is a simplified wrapper to Debian's package management tools including dpkg and APT. Wajig provides the functionality of apt-get, dpkg, dpkg-deb, apt-cache and other tools. These tools launch as a subprocess. Wajig also provides extra functionality beyond that of the stock apt and dpkg tools...

     is a simplified front end, providing the functionality of apt-get, dpkg
    Dpkg
    dpkg is the software at the base of the Debian package management system. dpkg is used to install, remove, and provide information about .deb packages....

    , dpkg-deb, apt-cache, and other tools.

Debian Live


A Debian Live
Debian Live
A Debian Live system is an instance of the Debian operating system which boots from removable media, without requiring installation or previous configuration. Supported removable media include CDs, DVDs, and USB flash drives ....

 system is a version of Debian that can be booted directly from removable media
Removable media
In computer storage, removable media refers to storage media which is designed to be removed from the computer without powering the computer off.Some types of removable media are designed to be read by removable readers and drives...

 (CDs, DVDs, USB keys) or via netboot
Network booting
Network booting is the process of booting a computer from a network rather than a local drive. This method of booting can be used by routers, diskless workstations and centrally managed computers such as public computers at libraries and schools...

 without having to install it on the hard drive. This allows the user to try out Debian before installing it or use it as a boot-disk. There are prebuilt Debian Live images for rescue, standard, GNOME
GNOME
GNOME is a desktop environment and graphical user interface that runs on top of a computer operating system. It is composed entirely of free and open source software...

, KDE Plasma Workspaces, Xfce
Xfce
Xfce is a free software desktop environment for Unix and other Unix-like platforms, such as Linux, Solaris, and BSD – though recent compatibility issues have arisen with regard to BSD Unix platforms...

 and LXDE
LXDE
LXDE is a free and open source desktop environment for Unix and other POSIX compliant platforms, such as Linux or BSD. The goal of the project is to provide a desktop environment that is fast and energy efficient...

 for several architectures. A hard disk installation can be achieved using the Debian Installer included in the live image. Most of the live ISO images for the current Squeeze release no longer fit on a 700MB CD. Customized CD images can be built using live-build. Live-build can not only generate CD Images, but also bootable DVDs, images for USB thumb drives, or netboot
Network booting
Network booting is the process of booting a computer from a network rather than a local drive. This method of booting can be used by routers, diskless workstations and centrally managed computers such as public computers at libraries and schools...

 images. Live-magic is a GUI
Graphical user interface
In computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...

 for live-build. Ging is a Debian GNU/kFreeBSD Live CD
Live CD
A live CD, live DVD, or live disc is a CD or DVD containing a bootable computer operating system. Live CDs are unique in that they have the ability to run a complete, modern operating system on a computer lacking mutable secondary storage, such as a hard disk drive...

.

Desktop environments


Debian offers stable and testing CD images specifically built for GNOME
GNOME
GNOME is a desktop environment and graphical user interface that runs on top of a computer operating system. It is composed entirely of free and open source software...

 (the default), KDE Plasma Workspaces, Xfce
Xfce
Xfce is a free software desktop environment for Unix and other Unix-like platforms, such as Linux, Solaris, and BSD – though recent compatibility issues have arisen with regard to BSD Unix platforms...

 and LXDE
LXDE
LXDE is a free and open source desktop environment for Unix and other POSIX compliant platforms, such as Linux or BSD. The goal of the project is to provide a desktop environment that is fast and energy efficient...

. Less common window manager
Window manager
A window manager is system software that controls the placement and appearance of windows within a windowing system in a graphical user interface. Most window managers are designed to help provide a desktop environment...

s such as Enlightenment
Enlightenment (window manager)
Enlightenment, also known simply as E, is a stacking window manager for the X Window System which can be used alone or in conjunction with a desktop environment such as GNOME or KDE...

, Openbox
Openbox
Openbox is a free window manager for the X Window System, licensed under the GNU General Public License. Originally derived from Blackbox 0.65.0 , Openbox has now been totally rewritten in the C programming language and since version 3.0 is not based upon any code from Blackbox.Openbox is designed...

, Fluxbox
Fluxbox
Fluxbox is a stacking window manager for the X Window System, which started as a fork of Blackbox 0.61.1, with the same aim to be lightweight. Its user interface has only a taskbar, a pop-up menu accessible by right-clicking on the desktop, and minimal support for graphical icons...

, GNUstep
GNUstep
GNUstep is a free software implementation of Cocoa Objective-C libraries , widget toolkit, and application development tools not only for Unix-like operating systems, but also for Microsoft Windows. It is part of the GNU Project.GNUstep features a cross-platform, object-oriented development...

, IceWM
IceWM
IceWM is a stacking window manager for the X Window System graphical infrastructure, written by Marko Maček. It was coded from scratch in C++ and is released under the terms of the GNU Lesser General Public License...

, Window Maker
Window Maker
Window Maker is a free and open source window manager for the X Window System, allowing graphical applications to be run on Unix-like operating-systems...

 and others can also be installed.

NAS support


Recent releases of Debian support an increasing number of ARM
ARM architecture
ARM is a 32-bit reduced instruction set computer instruction set architecture developed by ARM Holdings. It was named the Advanced RISC Machine, and before that, the Acorn RISC Machine. The ARM architecture is the most widely used 32-bit ISA in numbers produced...

-based NAS
Network-attached storage
Network-attached storage is file-level computer data storage connected to a computer network providing data access to heterogeneous clients. NAS not only operates as a file server, but is specialized for this task either by its hardware, software, or configuration of those elements...

 devices. The cheap NSLU2
NSLU2
The NSLU2 is a Network-attached storage device made by Linksys introduced in 2004 and discontinued in 2008. It makes USB Flash memory and hard disks accessible over a network using the SMB protocol...

 was supported by Debian 4.0 and 5.0 and can be upgraded to Debian 6.0 although there are problems with a 6.0 clean install. Debian 5.0 added support for the Buffalo
Buffalo network-attached storage series
The Buffalo network-attached storage series are network-attached storage devices.They can be modified into miniature general purpose Linux-based computers...

 Kurobox Pro, and Debian 6.0 for the SheevaPlug
SheevaPlug
The SheevaPlug is a "plug computer" designed to allow standard computing features in as small a space as possible.One of the first such computers on the market, the device has a 1.2 GHz Marvell Kirkwood 6281 ARM-compatible CPU . The operating system is Ubuntu Linux version 9.04...

.

Other NAS devices supported by Debian, but perhaps not so widely-used by home users, include GLAN Tank and Thecus N2100 as of Debian 4.0, QNAP Turbo Station (TS-109, TS-209, TS-409) and HP mv2120 as of Debian 5.0, and QNAP Turbo NAS TS-11x, TS-21x and TS-41x, OpenRD, Lanner EM7210 and Intel SS4000-e as of Debian 6.0.

1993–1998


Debian was first announced on 16 August 1993 by Ian Murdock
Ian Murdock
Ian Murdock is the founder of the Debian distribution and Progeny Linux Systems, a commercial Linux company.- Life and career :Murdock was born in Konstanz, Germany....

, who initially called the system "the Debian Linux Release". The word "Debian" was formed as a combination of the first name of his then-girlfriend Debra Lynn and his own first name. Prior to Debian's release, the Softlanding Linux System
Softlanding Linux System
Softlanding Linux System was an early Linux distribution founded by Peter MacDonald in May, 1992.SLS was the first release to offer a comprehensive Linux distribution containing more than the Linux kernel and basic utilities, including TCP/IP and the X Window System.- History :SLS was the most...

 (SLS) had been the first Linux distribution compiled from various software packages, and was a popular basis for other distributions in 1993-1994. The perceived poor maintenance and prevalence of bugs
Software bug
A software bug is the common term used to describe an error, flaw, mistake, failure, or fault in a computer program or system that produces an incorrect or unexpected result, or causes it to behave in unintended ways. Most bugs arise from mistakes and errors made by people in either a program's...

 in SLS motivated Murdock to launch a new distribution.

In 1993 Murdock also released the Debian Manifesto, outlining his view for the new operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...

. In it he called for the creation of a distribution
Linux distribution
A Linux distribution is a member of the family of Unix-like operating systems built on top of the Linux kernel. Such distributions are operating systems including a large collection of software applications such as word processors, spreadsheets, media players, and database applications...

 to be maintained in an open manner, in the spirit of Linux and GNU.

The Debian Project grew slowly at first and released the first 0.9x versions in 1994 and 1995. During this time it was sponsored by the Free Software Foundation
Free Software Foundation
The Free Software Foundation is a non-profit corporation founded by Richard Stallman on 4 October 1985 to support the free software movement, a copyleft-based movement which aims to promote the universal freedom to create, distribute and modify computer software...

's GNU Project
GNU Project
The GNU Project is a free software, mass collaboration project, announced on September 27, 1983, by Richard Stallman at MIT. It initiated GNU operating system development in January, 1984...

. The first ports to other, non-i386
Intel 80386
The Intel 80386, also known as the i386, or just 386, was a 32-bit microprocessor introduced by Intel in 1985. The first versions had 275,000 transistors and were used as the central processing unit of many workstations and high-end personal computers of the time...

 architectures began in 1995, and the first 1.x version of Debian was released in 1996.

In 1996, Bruce Perens
Bruce Perens
Bruce Perens is a computer programmer and advocate in the open source community. He created the Open Source Definition and published the first formal announcement and manifesto of open source. He co-founded the Open Source Initiative with Eric S...

 replaced Ian Murdock as the project leader. In the same year, Perens read a discussion between fellow developer Ean Schuessler
Ean Schuessler
Ean Schuessler is co-founder, with his brother Erik Schuessler, of Brainfood, Inc., a Dallas, Texas-based digital media consultancy. He is a long-time participant in the Debian project and collaborated in the creation of the Debian Social Contract which inspired the Open Source Definition...

 and Donnie Barnes of Red Hat, suggesting that Red Hat had stated no social contract
Social contract
The social contract is an intellectual device intended to explain the appropriate relationship between individuals and their governments. Social contract arguments assert that individuals unite into political societies by a process of mutual consent, agreeing to abide by common rules and accept...

 with its users which guaranteed the future freedom of the system's contents. Perens decided to create a social contract for Debian, created a first draft, and edited suggestions from a month-long the discussion on the Debian mailing lists into the Debian Social Contract
Debian Social Contract
The Debian Social Contract is a document which frames the moral agenda of the Debian project. The values outlined in the Social Contract provide the basic principles for the rules set forth in the Debian Free Software Guidelines...

 and the Debian Free Software Guidelines
Debian Free Software Guidelines
The Debian Free Software Guidelines is a set of guidelines that the Debian Project uses to determine whether a software license is a free software license, which in turn is used to determine whether a piece of software can be included in Debian...

, defining fundamental commitments for the development of the distribution. He also initiated the creation of the legal umbrella organization
Umbrella organization
An umbrella organization is an association of institutions, who work together formally to coordinate activities or pool resources. In business, political, or other environments, one group, the umbrella organization, provides resources and often an identity to the smaller organizations...

, Software in the Public Interest
Software in the Public Interest
Software in the Public Interest, Inc. is a non-profit organization formed to help other organizations create and distribute free/open-source software and open-source hardware...

.
Perens developed the project from 40 to 200 developers. He broke apart the "base system", the core packages of Debian, which had been maintained by Murdock alone, and distributed them to many maintainers. He led the conversion of the project from a.out to ELF
Executable and Linkable Format
In computing, the Executable and Linkable Format is a common standard file format for executables, object code, shared libraries, and core dumps. First published in the System V Application Binary Interface specification, and later in the Tool Interface Standard, it was quickly accepted among...

. He created the BusyBox
BusyBox
BusyBox provides several stripped-down Unix tools in a single executable. It runs in a variety of POSIX environments such as Linux, Android, FreeBSD and others, such as proprietary kernels, although many of the tools it provides are designed to work with interfaces provided by the Linux kernel. It...

 program to make it possible to run a Debian installer on a single floppy, and wrote a new installer. Perens was also responsible for many policy and design elements of Debian that persist to this day.
Perens left the project in 1998.

1999–2004


The Project elected new leaders and made two more 2.x releases, each including more ports and packages. The Advanced Packaging Tool
Advanced Packaging Tool
The Advanced Packaging Tool, or APT, is a free user interface that works with core libraries to handle the installation and removal of software on the Debian GNU/Linux distribution and its variants...

 was deployed during this time and the first port to a non-Linux kernel, Debian GNU/Hurd
Debian GNU/Hurd
Debian GNU/Hurd is the Debian project's distribution of the GNU operating system, using the GNU Hurd microkernel. Its developers are hoping to be able to release Debian GNU/Hurd for the next major release of Debian, "wheezy"....

, was started. The first Linux distribution
Linux distribution
A Linux distribution is a member of the family of Unix-like operating systems built on top of the Linux kernel. Such distributions are operating systems including a large collection of software applications such as word processors, spreadsheets, media players, and database applications...

s based on Debian, namely Libranet
Libranet
Libranet was an operating system based on Debian GNU/Linux.The last version released is Libranet 3.0, which cost about $90 in US dollars for new users, or $65 for existing Libranet users. The previous version, Libranet 2.8.1, became free to download.Development of Libranet has been discontinued...

, Corel Linux
Corel Linux
Corel Linux, also called Corel LinuxOS, was a Debian-based operating system made by Corel that was released in late 1999. Corel later discontinued the distribution, but did not remove the former Corel Open Source Development website until March 2002....

 and Stormix
Stormix
Stormix was a company that debuted its Debian-based Linux distribution with "Storm Linux 2000" in late 1999. Headquartered in the Harbour Centre, Vancouver, British Columbia, Stormix was an off-shoot of NetNation Communications, at the time, one of the top-ten web hosting companies...

's Storm Linux, were started in 1999. The 2.2 release in 2000 was dedicated to Joel Klecker, a developer who died of Duchenne muscular dystrophy
Duchenne muscular dystrophy
Duchenne muscular dystrophy is a recessive X-linked form of muscular dystrophy, which results in muscle degeneration, difficulty walking, breathing, and death. The incidence is 1 in 3,000 boys. Females and males are affected, though females are rarely affected and are more often carriers...

.

In late 2000, the project made major changes to archive and release management, reorganizing software archive processes with new "package pools" and creating a testing distribution as an ongoing, relatively stable staging area for the next release. In the same year, developers began holding an annual conference called DebConf
Debconf
DebConf is the yearly conference where Debian developers meet to discuss issues around the further development of the system.Besides the scheduled workshops and talks, Debian developers take the opportunity to hack on the Debian system in a more informal setting...

with talks and workshops for developers and technical users.

In July 2002, the Project released version 3.0, codenamed woody, (each Debian release is named after a character in the movie Toy Story
Toy Story
Toy Story is a 1995 American computer-animated film released by Walt Disney Pictures. It is Pixar's first feature film as well as the first ever feature film to be made entirely with CGI. The film was directed by John Lasseter and featuring the voices of Tom Hanks and Tim Allen...

), a stable release which would see relatively few updates until the following release.

The long release cycle employed by the Debian Project during this time drew considerable criticism from the free software community, and this triggered the creation of Ubuntu
Ubuntu (operating system)
Ubuntu is a computer operating system based on the Debian Linux distribution and distributed as free and open source software. It is named after the Southern African philosophy of Ubuntu...

 in 2004, to date one of the most influential Debian forks
Fork (software development)
In software engineering, a project fork happens when developers take a legal copy of source code from one software package and start independent development on it, creating a distinct piece of software...

.

2005–present


The 3.1 sarge release was made in June 2005. There were many major changes in the sarge release, mostly due to the large time it took to freeze and release the distribution. Not only did this release update over 73% of the software shipped in the previous version, but it also included much more software than previous releases, almost doubling in size with more than 9,000 new packages. A new installer replaced the aging boot-floppies installer with a modular design. This allowed advanced installations (with RAID, XFS and LVM support) including hardware detection, making installations easier for novice users. The installation system also boasted full internationalization support as the software was translated into almost forty languages. An installation manual and comprehensive release notes were released in ten and fifteen different languages respectively. This release included the efforts of the Debian-Edu/Skolelinux
Skolelinux
Skolelinux is an operating system intended for educational use and based on Debian .Skolelinux is a free and open source software project founded in Norway, now supporting all languages present in Debian...

, Debian-Med
Debian-Med
The Debian Med project is a Debian Pure Blend created to provide a co-ordinated operating system and collection of available free software packages that are well-suited for the requirements for medical practices and research.- Packages :...

 and Debian-Accessibility sub-projects which boosted the number of educational packages and those with a medical affiliation as well as packages designed especially for people with disabilities.

In 2006, as a result of a much-publicized dispute, Mozilla software was rebranded in Debian, with Firefox becoming Iceweasel, Thunderbird
Mozilla Thunderbird
Mozilla Thunderbird is a free, open source, cross-platform e-mail and news client developed by the Mozilla Foundation. The project strategy is modeled after Mozilla Firefox, a project aimed at creating a web browser...

 becoming Icedove, along with other Mozilla programs. The Mozilla Corporation stated that Debian may not use the Firefox trademark if it distributes Firefox with modifications which have not been approved by the Mozilla Corporation. Two prominent reasons that Debian modifies the Firefox software are to change the artwork, and to provide security patches. Debian Free Software Guidelines
Debian Free Software Guidelines
The Debian Free Software Guidelines is a set of guidelines that the Debian Project uses to determine whether a software license is a free software license, which in turn is used to determine whether a piece of software can be included in Debian...

 consider Mozilla's artwork non-free. Debian provides long term support for older versions of Firefox in the stable release, where Mozilla prefers that old versions are not supported. These software programs developed largely by the Mozilla Corporation were rebranded
Rebranding
Rebranding is the creation of a new name, term, symbol, design, or a combination of them for an established brand with the intention of developing a differentiated position in the mind of stakeholders and competitors....

 despite having only minor differences in the source code.

Debian 4.0 (etch) was released April 8, 2007 for the same number of architectures as in sarge. It included the AMD64 port but dropped support for m68k. The m68k port was, however, still available in the unstable distribution. There were approximately 18,200 binary packages maintained by more than 1,030 Debian developers.

Debian 5.0 (lenny) was released February 14, 2009 after 22 months of development. It includes more than 25,000 software packages. Support was added for Marvell's Orion platform and for netbooks such as the Asus Eee PC
ASUS Eee PC
The Asus Eee PC is a subnotebook/netbook computer line from ASUSTeK Computer Incorporated, and a part of the Asus Eee product family. At the time of its introduction in late 2007, it was noted for its combination of a light weight, Linux operating system, solid-state drive , and relatively low cost...

. The release was dedicated to Thiemo Seufer, an active developer and member of the community who died in a car accident on December 26, 2008.

On September 5, 2010, Debian officially acquired the backports
Backporting
Backporting is the action of taking a certain software modification and applying it to an older version of the software than it was initially created for. It is part of the maintenance step in a software development process....

 service, which provides more recent versions of some software for the stable release of Debian.

Debian 6.0 (squeeze) was released February 6, 2011 after 24 months of development. For the first time, Debian GNU/kFreeBSD was introduced with this version as a technology preview.

Project organization


The Debian Project is a volunteer organization with three foundational documents:
  • The Debian Social Contract
    Debian Social Contract
    The Debian Social Contract is a document which frames the moral agenda of the Debian project. The values outlined in the Social Contract provide the basic principles for the rules set forth in the Debian Free Software Guidelines...

     defines a set of basic principles by which the project and its developers conduct affairs.
  • The Debian Free Software Guidelines
    Debian Free Software Guidelines
    The Debian Free Software Guidelines is a set of guidelines that the Debian Project uses to determine whether a software license is a free software license, which in turn is used to determine whether a piece of software can be included in Debian...

     define the criteria for "free software" and thus what software is permissible in the distribution, as referenced in the Social Contract. These guidelines have also been adopted as the basis of the Open Source Definition. Although it can be considered a separate document for all practical purposes, it formally is part of the Social Contract.
  • The Debian Constitution describes the organizational structure for formal decision-making within the Project, and enumerates the powers and responsibilities of the Debian Project Leader, the Debian Project Secretary, and the Debian Developers generally.


Currently, the project includes more than a thousand developers. Each of them sustains some niche in the project, be it package maintenance, software documentation
Software documentation
Software documentation or source code documentation is written text that accompanies computer software. It either explains how it operates or how to use it, and may mean different things to people in different roles....

, maintaining the project infrastructure, quality assurance
Quality Assurance
Quality assurance, or QA for short, is the systematic monitoring and evaluation of the various aspects of a project, service or facility to maximize the probability that minimum standards of quality are being attained by the production process...

, or release coordination. Package maintainers have jurisdiction over their own packages, although packages are increasingly co-maintained. Other tasks are usually handled by the domain of smaller, more collaborative groups of developers.

The project maintains official mailing list
Mailing list
A mailing list is a collection of names and addresses used by an individual or an organization to send material to multiple recipients. The term is often extended to include the people subscribed to such a list, so the group of subscribers is referred to as "the mailing list", or simply "the...

s and conferences for communication and coordination between developers. For issues with single packages or domains, a public bug
Software bug
A software bug is the common term used to describe an error, flaw, mistake, failure, or fault in a computer program or system that produces an incorrect or unexpected result, or causes it to behave in unintended ways. Most bugs arise from mistakes and errors made by people in either a program's...

 tracking system is used by developers and end-users. Informally, Internet Relay Chat
Internet Relay Chat
Internet Relay Chat is a protocol for real-time Internet text messaging or synchronous conferencing. It is mainly designed for group communication in discussion forums, called channels, but also allows one-to-one communication via private message as well as chat and data transfer, including file...

 channels (primarily on the OFTC
Open and Free Technology Community
The Open and Free Technology Community is an IRC network that provides collaboration services to members of the free software community in any part of the world. OFTC is an associated project of Software in the Public Interest, a non-profit organization which was founded to help organizations...

 and freenode
Freenode
freenode, formerly known as Open Projects Network, is an IRC network used to discuss peer-directed projects. Their servers are all accessible from the domain name [irc://chat.freenode.net chat.freenode.net], which load balances connections by using the actual servers in rotation...

 networks) are used for communication among developers and users as well.

Together, the Developers may make binding general decisions by way of a General Resolution or election. All voting is conducted by Cloneproof Schwartz Sequential Dropping
Schulze method
The Schulze method is a voting system developed in 1997 by Markus Schulze that selects a single winner using votes that express preferences. The method can also be used to create a sorted list of winners...

, a Condorcet method
Condorcet method
A Condorcet method is any single-winner election method that meets the Condorcet criterion, which means the method always selects the Condorcet winner if such a candidate exists. The Condorcet winner is the candidate who would beat each of the other candidates in a run-off election.In modern...

 of voting. A Project Leader is elected once per year by a vote of the Developers; in April 2010, Stefano Zacchiroli was voted into this position, succeeding Steve McIntyre
Steve McIntyre
Steve McIntyre is a software engineer and a long-time Debian developer. His best known contributions have been in the field of creating Debian CD/DVD images; he is the debian-cd team leader and is responsible for generating the official images.McIntyre ran for the post of Debian Project Leader in...

. The Debian Project Leader has several special powers, but this power is far from absolute and is rarely used. Under a General Resolution, the Developers may, among other things, recall the leader, reverse a decision by him or his delegates, and amend the constitution and other foundational documents.

The Leader sometimes delegates authority to other developers in order for them to perform specialized tasks. Generally this means that a leader delegates someone to start a new group for a new task, and gradually a team gets formed that carries on doing the work and regularly expands or reduces their ranks as they think is best and as the circumstances allow.

A role in Debian with a similar importance to the Project Leader's is that of a Release Manager. Release Managers set goals for the next release, supervise the processes, and make the final decision as to when to release.

Project leaders


The Debian Project Leader (DPL) is the public face of the project and defines the current direction of the project. The project has had the following leaders:
  • Ian Murdock
    Ian Murdock
    Ian Murdock is the founder of the Debian distribution and Progeny Linux Systems, a commercial Linux company.- Life and career :Murdock was born in Konstanz, Germany....

     (August 1993: March 1996), founder of the Debian Project
  • Bruce Perens
    Bruce Perens
    Bruce Perens is a computer programmer and advocate in the open source community. He created the Open Source Definition and published the first formal announcement and manifesto of open source. He co-founded the Open Source Initiative with Eric S...

     (April 1996: December 1997)
  • Ian Jackson
    Ian Jackson
    Ian Jackson is a long time free software author and Debian developer. Jackson wrote dpkg, SAUCE, userv and debbugs. He used to maintain the Linux FAQ. He runs chiark.greenend.org.uk, a popular server, home to PuTTY among other things....

     (January 1998: December 1998)
  • Wichert Akkerman
    Wichert Akkerman
    Wichert Akkerman is a Dutch computer programmer, best known for his contributions to Debian, dpkg, Plone and strace.He was elected for two terms as the Debian Project Leader and served from January 1999 to March 2001. He was succeeded in that role by Ben Collins...

     (January 1999: March 2001)
  • Ben Collins (April 2001: April 2002)
  • Bdale Garbee
    Bdale Garbee
    Bdale Garbee is a computer specialist who works with GNU/Linux, particularly Debian. He is currently the GNU/Linux CTO at Hewlett-Packard and the current President of Software in the Public Interest....

     (April 2002: April 2003)
  • Martin Michlmayr
    Martin Michlmayr
    Dr. Martin Michlmayr is a Debian developer working on quality management.Michlmayr became a member of the Debian project in 2000 and soon began work as an Application Manager for membership applications. He subsequently worked as a member of the Front Desk which coordinates the New Maintainer...

     (March 2003: March 2005)
  • Branden Robinson
    Branden Robinson
    G. Branden Robinson is a Debian developer, known for his contributions to the packaging of the X Window System, and his tenure as the Debian Project Leader from April 2005 to April 2006.-Contributions:...

     (April 2005: April 2006)
  • Anthony Towns
    Anthony Towns
    Anthony Towns is a computer programmer who was a long-time Debian release manager, ftpmaster team member and later the Debian Project Leader...

     (April 2006: April 2007)
  • Sam Hocevar
    Sam Hocevar
    Samuel “Sam” Hocevar is a French computer scientist, programmer, image processing expert and reverse engineer. Hocevar was the Debian Project Leader from 17 April 2007 to 16 April 2008.- Biography :...

     (April 2007: April 2008)
  • Steve McIntyre
    Steve McIntyre
    Steve McIntyre is a software engineer and a long-time Debian developer. His best known contributions have been in the field of creating Debian CD/DVD images; he is the debian-cd team leader and is responsible for generating the official images.McIntyre ran for the post of Debian Project Leader in...

     (April 2008: April 2010)
  • Stefano Zacchiroli
    Stefano Zacchiroli
    Stefano Zacchiroli is the current Debian Project Leader, succeeding Steve McIntyre in April 2010. Zacchiroli became a Debian Developer in 2001...

     (April 2010: Present)


A supplemental position, Debian Second in Charge (2IC), was created by Anthony Towns. Steve McIntyre
Steve McIntyre
Steve McIntyre is a software engineer and a long-time Debian developer. His best known contributions have been in the field of creating Debian CD/DVD images; he is the debian-cd team leader and is responsible for generating the official images.McIntyre ran for the post of Debian Project Leader in...

 held the position between April 2006 and April 2007. From April 2009 to April 2010 this position was held by Luk Claes. Stefano Zacchiroli — the current project leader — abandoned this unofficial position when being elected in April 2010.

Release managers

  • Brian C. White (1997–1999)
  • Richard Braakman (1999–2000)
  • Anthony Towns
    Anthony Towns
    Anthony Towns is a computer programmer who was a long-time Debian release manager, ftpmaster team member and later the Debian Project Leader...

     (2000–2004)
  • Steve Langasek, Andreas Barth and Colin Watson (2004–2007)
  • Andreas Barth and Luk Claes (2007–2008)
  • Luk Claes and Marc Brockschmidt (2008–2009)
  • Luk Claes and Adeodato Simó (2009–2010)
  • Adam D. Barratt and Neil McGovern (2010–present)


Note that this list includes the active release managers; it does not include the release assistants (first introduced in 2003) and the retiring managers ("release wizards").

Developer recruitment, motivation, and resignation


The Debian project has a steady influx of applicants wishing to become developers. These applicants must undergo an elaborate vetting process which establishes their identity, motivation, understanding of the project's goals (embodied in the Social Contract
Debian Social Contract
The Debian Social Contract is a document which frames the moral agenda of the Debian project. The values outlined in the Social Contract provide the basic principles for the rules set forth in the Debian Free Software Guidelines...

), and technical competence.

Debian Developers join the Project for a number of reasons; some that have been cited in the past include:
  • A desire to contribute back to the free-software community (practically all applicants are users of free software
    Free software
    Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...

    )
  • A desire to see some specific software task accomplished (some view the Debian user community as a valuable testing or proving ground for new software)
  • A desire to make, or keep, free software competitive with proprietary alternatives
    Proprietary software
    Proprietary software is computer software licensed under exclusive legal right of the copyright holder. The licensee is given the right to use the software under certain conditions, while restricted from other uses, such as modification, further distribution, or reverse engineering.Complementary...

  • A desire to work closely with people who share some of their aptitudes, interests, and goals (there is a very strong sense of community
    Community
    The term community has two distinct meanings:*a group of interacting people, possibly living in close proximity, and often refers to a group that shares some common values, and is attributed with social cohesion within a shared geographical location, generally in social units larger than a household...

     within the Debian project which some applicants do not experience in their paid jobs)
  • A simple enjoyment of the iterative process of software development
    Software development
    Software development is the development of a software product...

     and maintenance


Debian Developers may resign their positions at any time by orphaning the packages they were responsible for and sending a notice to the developers and the keyring
Public key infrastructure
Public Key Infrastructure is a set of hardware, software, people, policies, and procedures needed to create, manage, distribute, use, store, and revoke digital certificates. In cryptography, a PKI is an arrangement that binds public keys with respective user identities by means of a certificate...

 maintainer (so that their upload authorization can be revoked).

Development procedures


Software packages in development are either uploaded to the project distribution named unstable (also known as sid), or to the experimental repository. Software packages uploaded to unstable are normally versions stable enough to be released by the original upstream developer, but with the added Debian-specific packaging and other modifications introduced by Debian developers. These additions may be new and untested. Software not ready yet for the unstable distribution is typically placed in the experimental repository.

After a version of a software package has remained in unstable for a certain length of time (depending on the urgency of the software's changes), that package is automatically migrated to the testing distribution. The package's migration to testing occurs only if no serious (release-critical) bugs in the package are reported and if other software needed for package functionality qualifies for inclusion in testing.

Since updates to Debian software packages between official releases do not contain new features, some choose to use the testing and unstable distributions for their newer packages. However, these distributions are less tested than stable, and unstable does not receive timely security updates. In particular, incautious upgrades to working unstable packages can sometimes seriously break software functionality. Since September 9, 2005 the testing distribution's security updates have been provided by the testing security team.

After the packages in testing have matured and the goals for the next release are met, the testing distribution becomes the next stable release. The timing of the release is decided by the Release Managers, and in the past the exact date was rarely announced earlier than a couple of weeks beforehand.

Package maintenance


Each Debian software package has a maintainer who keeps track of releases by the "upstream" authors of the software and ensures that the package is compliant with Debian Policy, coheres with the rest of the distribution, and meets the standards of quality of Debian. In relations with users and other developers, the maintainer uses the bug tracking system to follow up on bug reports and fix bugs. Typically, there is only one maintainer for a single package, but, increasingly, small teams of developers "co-maintain" larger and more complex packages and groups of packages.

Periodically, a package maintainer makes a release of a package by uploading it to the "incoming" directory of the Debian package archive (or an "upload queue" which periodically batch-transmits packages to the incoming directory). Package uploads are automatically processed to ensure that they are well-formed (all the requisite files are in place) and that the package is digitally signed
Digital signature
A digital signature or digital signature scheme is a mathematical scheme for demonstrating the authenticity of a digital message or document. A valid digital signature gives a recipient reason to believe that the message was created by a known sender, and that it was not altered in transit...

 by a Debian developer using OpenPGP-compatible software. All Debian developers have individual cryptographic key pairs
Public-key cryptography
Public-key cryptography refers to a cryptographic system requiring two separate keys, one to lock or encrypt the plaintext, and one to unlock or decrypt the cyphertext. Neither key will do both functions. One of these keys is published or public and the other is kept private...

. Packages are signed to be able to reject uploads from hostile outsiders to the project, and to permit accountability in the event that a package contains a serious bug
Software bug
A software bug is the common term used to describe an error, flaw, mistake, failure, or fault in a computer program or system that produces an incorrect or unexpected result, or causes it to behave in unintended ways. Most bugs arise from mistakes and errors made by people in either a program's...

, a violation of policy, or malicious code.

If the package in incoming is found to be validly signed and well-formed, it is installed into the archive into an area called the "pool" and distributed every day to hundreds of mirrors
Mirror (computing)
In computing, a mirror is an exact copy of a data set. On the Internet, a mirror site is an exact copy of another Internet site.Mirror sites are most commonly used to provide multiple sources of the same information, and are of particular value as a way of providing reliable access to large downloads...

 worldwide. Initially, all package uploads accepted into the archive are only available in the "unstable" suite of packages, which contains the most up-to-date version of each package.

However, new code is also untried code, and those packages are only distributed with clear disclaimers. For packages to become candidates for the next "stable" release of the Debian distribution, they first need to be included in the "testing" suite. For a package to be included in testing:
  • It must have been in unstable for the appropriate length of time (the exact duration depends on the "urgency" of the upload)
  • It must not have a greater number of "release-critical" bugs filed against it than the current version in testing. Release-critical bugs are those bugs which are considered serious enough that they make the package unsuitable for release.
  • It must be compiled for all release architectures the package claims to support (e.g.: the i386-specific package gmod can be included in "testing")
  • All of its dependencies must either be satisfiable by packages already in testing, or be satisfiable by the group of packages which are going to be installed at the same time.
  • The operation of installing the package into testing must not break any packages currently in testing.


Thus, a release-critical bug in a package on which many packages depend, such as a shared library, may prevent many packages from entering the testing area, because that library is considered deficient.

Periodically, the Release Manager publishes guidelines to the developers in order to ready the release, and in accordance with them eventually decides to make a release. This occurs when all important software is reasonably up-to-date in the release-candidate suite for all architectures for which a release is planned, and when any other goals set by the Release Manager have been met. At that time, all packages in the release-candidate suite ("testing") become part of the released suite ("stable").

It is possible for a package: particularly an old, stable, and seldom-updated one: to belong to more than one suite at the same time. The suites are simply collections of pointers into the package "pool" mentioned above.

Security information and policy


The Debian Project, being free software, handles security policy through public disclosure
Full disclosure
In computer security, full disclosure means to disclose all the details of a security problem which are known. It is a philosophy of security management completely opposed to the idea of security through obscurity...

 rather than through security through obscurity
Security through obscurity
Security through obscurity is a pejorative referring to a principle in security engineering, which attempts to use secrecy of design or implementation to provide security...

. Many advisories are coordinated with other free software vendors (Debian is a member of vendor-sec
Vendor-sec
vendor-sec was an electronic mailing list dedicated to distributors of operating systems using free and open-source software...

) and are published the same day a vulnerability is made public. Debian has a security audit team that reviews the archive looking for new or unfixed security bugs. Debian also participates in security standardization efforts: the Debian security advisories are compatible with the Common Vulnerabilities and Exposures
Common Vulnerabilities and Exposures
The Common Vulnerabilities and Exposures or CVE system provides a reference-method for publicly-known information-security vulnerabilities and exposures. MITRE Corporation maintains the system, with funding from the National Cyber Security Division of the United States Department of Homeland...

 (CVE) dictionary, and Debian is represented in the Board of the Open Vulnerability and Assessment Language
Open Vulnerability and Assessment Language
Open Vulnerability and Assessment Language is an international, information security, community standard to promote open and publicly available security content, and to standardize the transfer of this information across the entire spectrum of security tools and services...

 (OVAL) project.

The Debian Project offers extensive documentation and tools to harden a Debian installation both manually and automatically. SELinux
Security-Enhanced Linux
Security-Enhanced Linux is a Linux feature that provides a mechanism for supporting access control security policies, including United States Department of Defense-style mandatory access controls, through the use of Linux Security Modules in the Linux kernel...

 (Security-Enhanced Linux) packages are installed by default though not enabled. Debian provides an optional hardening wrapper but does not compile their packages by default using gcc
GNU Compiler Collection
The GNU Compiler Collection is a compiler system produced by the GNU Project supporting various programming languages. GCC is a key component of the GNU toolchain...

 features such as PIE
Position-independent code
In computing, position-independent code or position-independent executable is machine instruction code that executes properly regardless of where in memory it resides...

 and Buffer overflow protection to harden their software, unlike Ubuntu
Ubuntu (operating system)
Ubuntu is a computer operating system based on the Debian Linux distribution and distributed as free and open source software. It is named after the Southern African philosophy of Ubuntu...

, Fedora
Fedora (operating system)
Fedora is a RPM-based, general purpose collection of software, including an operating system based on the Linux kernel, developed by the community-supported Fedora Project and sponsored by Red Hat...

 and Hardened Gentoo
Hardened Gentoo
Hardened Gentoo is a project of Gentoo Linux that is enhancing the distribution with security addons. Current security enhancements to Gentoo Linux can be:*SELinux**A system of mandatory access controls...

 among others. These extra features greatly increase security at the performance expense of 1% in 32 bit and 0.01% in 64 bit
X86-64
x86-64 is an extension of the x86 instruction set. It supports vastly larger virtual and physical address spaces than are possible on x86, thereby allowing programmers to conveniently work with much larger data sets. x86-64 also provides 64-bit general purpose registers and numerous other...

.

Releases


, the latest stable release is version 6.0, code name squeeze. When a new version is released, the previous stable version becomes oldstable; currently version 5.0, code name lenny.

In addition, a stable release gets minor updates (called point releases). The numbering scheme for the point releases up to Debian 4.0 was to include the letter r (for release) after the main version number (e.g. 4.0) and then the number of the point release; for example, the latest point release of version 4.0 (etch) as of 8 December 2010 is 4.0r9. From Debian 5.0 (lenny), the numbering scheme of point releases has been changed and conforms to the GNU version numbering standard; so, for example, the first point release of Debian 5.0 was 5.0.1 (instead of 5.0r1).

The Debian security team releases security updates for the latest stable major release, as well as for the previous stable release for one year. Version 4.0 etch was released on 8 April 2007, and the security team supported version 3.1 Sarge until 21 March 2008. For most uses it is strongly recommended to run a system which receives security updates. The testing distribution also receives security updates, but not in as timely a manner as stable.

For Debian 6.0 (squeeze) a new policy of time-based development freezes on a two-year cycle was announced. Time-based freezes are intended to allow the Debian Project to blend the predictability of time based releases with its policy of feature based releases. The new freeze policy aims to provide better predictability of releases for users of the Debian distribution, and to allow Debian developers to do better long-term planning. Debian developers expect that a two-year release cycle will give more time for disruptive changes, reducing inconveniences caused for users. Having predictable freezes was expected to reduce overall freeze time. The squeeze cycle was intended to be especially short to "get into the new cycle". However this short freeze cycle for squeeze was abandoned.

The code names of Debian releases are names of characters from the film Toy Story
Toy Story
Toy Story is a 1995 American computer-animated film released by Walt Disney Pictures. It is Pixar's first feature film as well as the first ever feature film to be made entirely with CGI. The film was directed by John Lasseter and featuring the voices of Tom Hanks and Tim Allen...

. The unstable, development distribution is permanently nicknamed sid, after the emotionally unstable next-door neighbor boy who regularly destroyed toys. The release after squeeze will be named wheezy, after the rubber toy penguin in Toy Story 2
Toy Story 2
Toy Story 2 is a 1999 American computer animated film directed by John Lasseter and co-directed by Lee Unkrich and Ash Brannon. It is the sequel to the 1995 film Toy Story, released by Walt Disney Pictures and the third film to be produced by Pixar...

.

Release history


Debian has made eleven major stable releases:
Legend
Release no longer supported
Release still supported
Future release

TBA stands for to be announced.
Version Code name
Code name
A code name or cryptonym is a word or name used clandestinely to refer to another name or word. Code names are often used for military purposes, or in espionage...

Release date Ports Packages Supported until Notes
1.1 buzz 17 June 1996 1 474 1996-09 dpkg, ELF
Executable and Linkable Format
In computing, the Executable and Linkable Format is a common standard file format for executables, object code, shared libraries, and core dumps. First published in the System V Application Binary Interface specification, and later in the Tool Interface Standard, it was quickly accepted among...

 transition, Linux 2.0
1.2 rex 12 December 1996 1 848 1996 -
1.3 bo 5 June 1997 1 974 1997 -
2.0 hamm 24 July 1998 2 ≈ 1,500 1998 glibc
GNU C Library
The GNU C Library, commonly known as glibc, is the C standard library released by the GNU Project. Originally written by the Free Software Foundation for the GNU operating system, the library's development has been overseen by a committee since 2001, with Ulrich Drepper from Red Hat as the lead...

 transition, new architecture: m68k
2.1 slink 9 March 1999 4 ≈ 2,250 2000-12 APT, new architectures: alpha, sparc
2.2 potato 15 August 2000 6 ≈ 3,900 2003-04 New architectures: arm, powerpc
3.0 woody 19 July 2002 11 ≈ 8,500 2006-08 New architectures: hppa, ia64, mips, mipsel, s390
3.1 sarge 6 June 2005 11 ≈ 15,400 2008-04 Modular installer, semi-official amd64 support.
4.0 etch 8 April 2007 11 ≈ 18,000 2010-02-15 New architecture: amd64, dropped architecture: m68k. Graphical installer, udev
Udev
udev is the device manager for the Linux kernel. Primarily, it manages device nodes in /dev. It is the successor of devfs and hotplug, which means that it handles the /dev directory and all user space actions when adding/removing devices, including firmware load.-History:udev was new in Linux...

 transition, modular X.Org
X.Org Server
X.Org Server refers to the X server release packages stewarded by the X.Org Foundation,which is hosted by freedesktop.org, and grants...

 transition. Latest update 4.0r9 was released 2010-05-22
5.0 lenny 14 February 2009 11+1 ≈ 23,000 TBA New architecture/binary ABI: armel. SPARC
SPARC
SPARC is a RISC instruction set architecture developed by Sun Microsystems and introduced in mid-1987....

 32-bit hardware support dropped. Full Eee PC
ASUS Eee PC
The Asus Eee PC is a subnotebook/netbook computer line from ASUSTeK Computer Incorporated, and a part of the Asus Eee product family. At the time of its introduction in late 2007, it was noted for its combination of a light weight, Linux operating system, solid-state drive , and relatively low cost...

 support. Latest update 5.0.9 was released 2011-10-01.
6.0 squeeze 6 February 2011 9+2 ≈ 29,000 TBA New architectures/kernels: kfreebsd-i386, kfreebsd-amd64, dropped architectures: alpha, hppa, OABI arm. eglibc
Embedded GLIBC
Embedded GLIBC is a variant of the GNU C Library , optimised for use in embedded devices, while still attempting to remain source and binary compatible with the standard glibc...

 instead of glibc
GNU C Library
The GNU C Library, commonly known as glibc, is the C standard library released by the GNU Project. Originally written by the Free Software Foundation for the GNU operating system, the library's development has been overseen by a committee since 2001, with Ulrich Drepper from Red Hat as the lead...

. Dependency-based boot sequence, which allows for parallel init script processing. Remove old libraries such as GTK 1. Default Linux kernel purged of non-free firmware.
7.0 wheezy 2012 TBA TBA TBA Remove old libraries such as Qt3. Introduce multiarch support.
11 architectures + 1 additional ARM binary ABI (armel)
9 architectures with Linux kernel + 2 architectures with kernel of FreeBSD

Due to an incident involving a CD vendor who made an unofficial and broken release labeled 1.0, an official 1.0 release was never made.

Kernels

Debian release Debian kernel
Kernel (computing)
In computing, the kernel is the main component of most computer operating systems; it is a bridge between applications and the actual data processing done at the hardware level. The kernel's responsibilities include managing the system's resources...

Latest kernel version just before the Debian release
1.1 buzz on 17 June 1996 2.0 on 9 June 1996
1.2 rex on 12 December 1996 2.0.27 on 1 December 1996
1.3 bo on 5 June 1997 2.0.29
2.0.30
for 1.3.1 also 2.0.33
2.0.30 on 8 April 1997
2.1.42 on 29 May 1997
2.0 hamm on 24 July 1998 2.0.33
2.0.34
2.0.35 on 13 July 1998
2.1.110 on 21 July 1998
2.1 slink on 9 March 1999 2.0.35-3
2.0.36-3
2.1.125-1
2.2.1-1
2.2.3 on 9 March 1999
2.2 potato on 15 August 2000 2.2.16 2.2.16 on 7 June 2000
2.3.99-pre9 on 23 May 2000
3.0 woody on 19 July 2002 2.2.20
2.4.18
2.2.21 on 20 May 2002
2.4.18 on 25 February 2002
2.5.26 on 16 July 2002
3.1 sarge on 6 June 2005 2.6.8>2.4.30 on 4 April 2005
2.6.11.11 on 27 May 2005
4.0 etch on 8 April 2007 2.6.18 2.6.20.6 on 6 April 2007
5.0 lenny on 14 February 2009 2.6.26 2.6.28.5 on 12 February 2009
6.0 squeeze on 6 February 2011 Linux 2.6.32
kFreeBSD 8.1
2.6.37 on 5 January 2011
8.1 on 19 July 2010

Distributions


The Debian Project offers three distributions, each with different characteristics. The distributions include packages which comply with the Debian Free Software Guidelines
Debian Free Software Guidelines
The Debian Free Software Guidelines is a set of guidelines that the Debian Project uses to determine whether a software license is a free software license, which in turn is used to determine whether a piece of software can be included in Debian...

 (DFSG), which are included inside the main repositories.
  • stable, currently aliased squeeze, is the current release that has stable and well-tested software. Stable is made by freezing testing for a few months where bugs are fixed to make the distribution as stable as possible; then the resulting system is released as stable. It is updated only if major security or usability fixes are incorporated. After Debian 6.0, new releases will be made every two years. Stable's CDs and DVDs can be found in the Debian web site.
  • testing, currently aliased wheezy, is what the next major release will be and is currently being tested. The packages included in this distribution have had some testing in unstable but they may not be completely fit for release yet. It contains more modern packages than stable but older than unstable. This distribution is updated continually until it enters the "frozen" state. Security updates for testing distribution are provided by Debian testing security team. Testing's CDs and DVDs can be found on the Debian web site.
  • unstable, permanently aliased sid, repository contains packages currently under development; it is updated continually. This repository is designed for Debian developers who participate in a project and need the latest libraries available, or for those who like to "live on the edge", therefore it will not be as stable as the other distributions. There are no official CDs/DVDs because it is rapidly changing and the project does not support it, although CD and DVD images of sid are built quarterly by aptosid. Additionally, the other two distributions can be upgraded to unstable.

Additional repositories


The Debian Free Software Guidelines
Debian Free Software Guidelines
The Debian Free Software Guidelines is a set of guidelines that the Debian Project uses to determine whether a software license is a free software license, which in turn is used to determine whether a piece of software can be included in Debian...

 (DFSG) adhere to a relatively strict interpretation of free and open source software
Free and open source software
Free and open-source software or free/libre/open-source software is software that is liberally licensed to grant users the right to use, study, change, and improve its design through the availability of its source code...

 (FOSS), although it is still not endorsed by the Free Software Foundation
Free Software Foundation
The Free Software Foundation is a non-profit corporation founded by Richard Stallman on 4 October 1985 to support the free software movement, a copyleft-based movement which aims to promote the universal freedom to create, distribute and modify computer software...

 as it includes and supports a proprietary
Proprietary software
Proprietary software is computer software licensed under exclusive legal right of the copyright holder. The licensee is given the right to use the software under certain conditions, while restricted from other uses, such as modification, further distribution, or reverse engineering.Complementary...

 repository, documentation that recommends non-free software and includes binary blobs. In accordance with its guidelines, a relatively small number of packages are excluded from the distributions' main repositories and included inside the non-free and contrib repositories. These two repositories are not officially part of Debian GNU/Linux.
  • non-free: repositories include packages which do not comply with the DFSG (this does usually not include legally questionable packages, like libdvdcss
    Libdvdcss
    libdvdcss is a free software library for accessing and unscrambling DVDs encrypted with the Content Scramble System...

    ).
  • contrib: repositories include packages which do comply with the DFSG, but may fail other requirements. For instance, they may depend on packages which are in non-free or requires such for building them.


These are other repositories available in Debian:
  • experimental: is not actually a full (self-contained) development distribution, it is meant to be a temporary staging area for highly experimental software. Dependencies missing are most likely found in unstable. Debian warns that these packages are likely unstable or buggy and are to be used at the user's own risk.
  • backports: This repository provides more recent versions than stable for some software. It is mainly intended for users of stable who need a newer version of a particular package.
  • oldstable, presently aliased lenny, is the previous stable release. It is supported until 1 year after a new stable is released. Debian recommends to update to the new stable once it has been released.
  • snapshot: The snapshot repositories provide older versions of other repositories. They may be used to install a specific older version of some software.

Third-party repositories


These repositories are not part of the Debian Project, they are maintained by third party organizations. They contain packages that are either more modern than the ones found in stable or include packages that are not included in the Debian Project for a variety of reasons such as: e.g. alleged possible patent infringement, binary-only/no sources, or special too restrictive licenses. Their use requires precise configuration of the priority of the repositories to be merged; otherwise these packages may not integrate correctly into the system, and may cause problems upgrading or conflicts between packages from different sources. The Debian Project discourages the use of these repositories as they are not part of the project.

Repository access


Debian provides repositories
Software repository
A software repository is a storage location from which software packages may be retrieved and installed on a computer.- Discussion :Many software publishers and other organizations maintain servers on the Internet for this purpose, either free of charge or for a subscription fee...

 of more than twenty nine thousand installable packages. Any of the repositories can be added or modified by directly editing the files in /etc/apt/sources.list or modifying the settings in APT
Advanced Packaging Tool
The Advanced Packaging Tool, or APT, is a free user interface that works with core libraries to handle the installation and removal of software on the Debian GNU/Linux distribution and its variants...

 front-ends. This is an example of the contents of this file:


deb http://ftp.us.debian.org/debian squeeze main contrib non-free

Hardware requirements


Debian has no hardware requirements beyond those of the Linux kernel
Linux kernel
The Linux kernel is an operating system kernel used by the Linux family of Unix-like operating systems. It is one of the most prominent examples of free and open source software....

 and the GNU
GNU
GNU is a Unix-like computer operating system developed by the GNU project, ultimately aiming to be a "complete Unix-compatible software system"...

 tool-sets (gcc
GNU Compiler Collection
The GNU Compiler Collection is a compiler system produced by the GNU Project supporting various programming languages. GCC is a key component of the GNU toolchain...

, coreutils
GNU Core Utilities
The GNU Core Utilities or coreutils is a package of GNU software containing many of the basic tools, such as cat, ls, and rm, needed for Unix-like operating systems...

, bash, etc.). Therefore, any architecture or platform to which these packages have been ported, and for which a Debian port exists, can run Debian.

Linux, and therefore Debian, supports many processors or "symmetric multiprocessing
Symmetric multiprocessing
In computing, symmetric multiprocessing involves a multiprocessor computer hardware architecture where two or more identical processors are connected to a single shared main memory and are controlled by a single OS instance. Most common multiprocessor systems today use an SMP architecture...

". This does not inhibit support for single-processor systems.

Debian's recommended system requirements differ depending on the level of installation, which corresponds to increased numbers of installed components:
Install Type Minimal RAM
Random-access memory
Random access memory is a form of computer data storage. Today, it takes the form of integrated circuits that allow stored data to be accessed in any order with a worst case performance of constant time. Strictly speaking, modern types of DRAM are therefore not random access, as data is read in...

Recommended RAM
Random-access memory
Random access memory is a form of computer data storage. Today, it takes the form of integrated circuits that allow stored data to be accessed in any order with a worst case performance of constant time. Strictly speaking, modern types of DRAM are therefore not random access, as data is read in...

Hard Drive space used
No Desktop 64 MB
Megabyte
The megabyte is a multiple of the unit byte for digital information storage or transmission with two different values depending on context: bytes generally for computer memory; and one million bytes generally for computer storage. The IEEE Standards Board has decided that "Mega will mean 1 000...

256 MB
Megabyte
The megabyte is a multiple of the unit byte for digital information storage or transmission with two different values depending on context: bytes generally for computer memory; and one million bytes generally for computer storage. The IEEE Standards Board has decided that "Mega will mean 1 000...

1 GB
Gigabyte
The gigabyte is a multiple of the unit byte for digital information storage. The prefix giga means 109 in the International System of Units , therefore 1 gigabyte is...

With Desktop 128 MB
Megabyte
The megabyte is a multiple of the unit byte for digital information storage or transmission with two different values depending on context: bytes generally for computer memory; and one million bytes generally for computer storage. The IEEE Standards Board has decided that "Mega will mean 1 000...

512 MB
Megabyte
The megabyte is a multiple of the unit byte for digital information storage or transmission with two different values depending on context: bytes generally for computer memory; and one million bytes generally for computer storage. The IEEE Standards Board has decided that "Mega will mean 1 000...

5 GB
Gigabyte
The gigabyte is a multiple of the unit byte for digital information storage. The prefix giga means 109 in the International System of Units , therefore 1 gigabyte is...



A 1 GHz processor
Central processing unit
The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...

 is the minimum recommended for desktop systems.

The real minimum memory requirements are much less than the numbers listed in this table. Depending on the architecture
Computer architecture
In computer science and engineering, computer architecture is the practical art of selecting and interconnecting hardware components to create computers that meet functional, performance and cost goals and the formal modelling of those systems....

, it is possible to install Debian with as little as 20 MB
Megabyte
The megabyte is a multiple of the unit byte for digital information storage or transmission with two different values depending on context: bytes generally for computer memory; and one million bytes generally for computer storage. The IEEE Standards Board has decided that "Mega will mean 1 000...

 for s390 or 48 MB
Megabyte
The megabyte is a multiple of the unit byte for digital information storage or transmission with two different values depending on context: bytes generally for computer memory; and one million bytes generally for computer storage. The IEEE Standards Board has decided that "Mega will mean 1 000...

 for i386 and amd64
X86-64
x86-64 is an extension of the x86 instruction set. It supports vastly larger virtual and physical address spaces than are possible on x86, thereby allowing programmers to conveniently work with much larger data sets. x86-64 also provides 64-bit general purpose registers and numerous other...

. Similarly, disk space requirements, which depend on the packages to be installed, can also be reduced.

It is possible to run graphical user interface
Graphical user interface
In computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...

s on older or low-end systems, but it is recommended to install window manager
Window manager
A window manager is system software that controls the placement and appearance of windows within a windowing system in a graphical user interface. Most window managers are designed to help provide a desktop environment...

s instead of desktop environment
Desktop environment
In graphical computing, a desktop environment commonly refers to a style of graphical user interface derived from the desktop metaphor that is seen on most modern personal computers. These GUIs help the user in easily accessing, configuring, and modifying many important and frequently accessed...

s, which are more resource-intensive. For example, the LXDE
LXDE
LXDE is a free and open source desktop environment for Unix and other POSIX compliant platforms, such as Linux or BSD. The goal of the project is to provide a desktop environment that is fast and energy efficient...

 desktop environment
Desktop environment
In graphical computing, a desktop environment commonly refers to a style of graphical user interface derived from the desktop metaphor that is seen on most modern personal computers. These GUIs help the user in easily accessing, configuring, and modifying many important and frequently accessed...

 was released with lenny and has much lower processor and memory usages compared with GNOME
GNOME
GNOME is a desktop environment and graphical user interface that runs on top of a computer operating system. It is composed entirely of free and open source software...

 or KDE Plasma Desktop.

Depending on the nature of the server, RAM
Random-access memory
Random access memory is a form of computer data storage. Today, it takes the form of integrated circuits that allow stored data to be accessed in any order with a worst case performance of constant time. Strictly speaking, modern types of DRAM are therefore not random access, as data is read in...

 and disk space requirements can vary widely.

Stable ports


As of the current stable release, the official ports are:
  • i386: x86 architecture designed for Intel/AMD 32-bit PCs
    IBM PC compatible
    IBM PC compatible computers are those generally similar to the original IBM PC, XT, and AT. Such computers used to be referred to as PC clones, or IBM clones since they almost exactly duplicated all the significant features of the PC architecture, facilitated by various manufacturers' ability to...

    . Also compatible but not recommended on Intel/AMD 64-bit single/multi core PCs
    IBM PC compatible
    IBM PC compatible computers are those generally similar to the original IBM PC, XT, and AT. Such computers used to be referred to as PC clones, or IBM clones since they almost exactly duplicated all the significant features of the PC architecture, facilitated by various manufacturers' ability to...

  • amd64: x86-64
    X86-64
    x86-64 is an extension of the x86 instruction set. It supports vastly larger virtual and physical address spaces than are possible on x86, thereby allowing programmers to conveniently work with much larger data sets. x86-64 also provides 64-bit general purpose registers and numerous other...

     architecture designed for Intel/AMD 64-bit single/multi core PCs
    IBM PC compatible
    IBM PC compatible computers are those generally similar to the original IBM PC, XT, and AT. Such computers used to be referred to as PC clones, or IBM clones since they almost exactly duplicated all the significant features of the PC architecture, facilitated by various manufacturers' ability to...

  • armel: little-endian
    Endianness
    In computing, the term endian or endianness refers to the ordering of individually addressable sub-components within the representation of a larger data item as stored in external memory . Each sub-component in the representation has a unique degree of significance, like the place value of digits...

     ARM architecture
    ARM architecture
    ARM is a 32-bit reduced instruction set computer instruction set architecture developed by ARM Holdings. It was named the Advanced RISC Machine, and before that, the Acorn RISC Machine. The ARM architecture is the most widely used 32-bit ISA in numbers produced...

     on RiscPC and various embedded systems (EABI)
  • sparc: Sun SPARC
    SPARC
    SPARC is a RISC instruction set architecture developed by Sun Microsystems and introduced in mid-1987....

     architecture on sun4u/v
    Sun-4
    Sun-4 is a series of Unix workstations and servers produced by Sun Microsystems, launched in 1987. The original Sun-4 series were VMEbus-based systems similar to the earlier Sun-3 series, but employing microprocessors based on Sun's own SPARC V7 RISC architecture in place of the 68k family...

     systems
  • powerpc: PowerPC
    PowerPC
    PowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...

     architecture
  • ia64: Intel Itanium
    Itanium
    Itanium is a family of 64-bit Intel microprocessors that implement the Intel Itanium architecture . Intel markets the processors for enterprise servers and high-performance computing systems...

     (IA-64) architecture
  • mips, mipsel: MIPS architecture
    MIPS architecture
    MIPS is a reduced instruction set computer instruction set architecture developed by MIPS Technologies . The early MIPS architectures were 32-bit, and later versions were 64-bit...

     (big-endian and little-endian)
  • s390: IBM ESA/390 architecture and z/Architecture
    Z/Architecture
    z/Architecture, initially and briefly called ESA Modal Extensions , refers to IBM's 64-bit computing architecture for IBM mainframe computers. IBM introduced its first z/Architecture-based system, the zSeries Model 900, in late 2000. Later z/Architecture systems include the IBM z800, z990, z890,...



and as a "technology preview":
  • kfreebsd-i386: Kernel of FreeBSD
    FreeBSD
    FreeBSD is a free Unix-like operating system descended from AT&T UNIX via BSD UNIX. Although for legal reasons FreeBSD cannot be called “UNIX”, as the direct descendant of BSD UNIX , FreeBSD’s internals and system APIs are UNIX-compliant...

     on 32 bit architecture
  • kfreebsd-amd64: Kernel of FreeBSD
    FreeBSD
    FreeBSD is a free Unix-like operating system descended from AT&T UNIX via BSD UNIX. Although for legal reasons FreeBSD cannot be called “UNIX”, as the direct descendant of BSD UNIX , FreeBSD’s internals and system APIs are UNIX-compliant...

     on 64 bit
    X86-64
    x86-64 is an extension of the x86 instruction set. It supports vastly larger virtual and physical address spaces than are possible on x86, thereby allowing programmers to conveniently work with much larger data sets. x86-64 also provides 64-bit general purpose registers and numerous other...

     architecture

Unstable ports


In addition to the stable ports, in the official unstable distribution are:
  • hurd-i386: GNU Hurd
    GNU Hurd
    GNU Hurd is a free software Unix-like replacement for the Unix kernel, released under the GNU General Public License. It has been under development since 1990 by the GNU Project of the Free Software Foundation...

     kernel on 32 bit architecture
  • armhf: ARM
    ARM architecture
    ARM is a 32-bit reduced instruction set computer instruction set architecture developed by ARM Holdings. It was named the Advanced RISC Machine, and before that, the Acorn RISC Machine. The ARM architecture is the most widely used 32-bit ISA in numbers produced...

     hard-float architecture requiring hardware with a floating-point unit (FPU)
  • s390x: IBM ESA/390 architecture and z/Architecture
    Z/Architecture
    z/Architecture, initially and briefly called ESA Modal Extensions , refers to IBM's 64-bit computing architecture for IBM mainframe computers. IBM introduced its first z/Architecture-based system, the zSeries Model 900, in late 2000. Later z/Architecture systems include the IBM z800, z990, z890,...

     with 64-bit userland


Unofficial ports are also available as part of the unstable distribution at http://www.debian-ports.org:
  • alpha: DEC Alpha
    DEC Alpha
    Alpha, originally known as Alpha AXP, is a 64-bit reduced instruction set computer instruction set architecture developed by Digital Equipment Corporation , designed to replace the 32-bit VAX complex instruction set computer ISA and its implementations. Alpha was implemented in microprocessors...

     architecture
  • avr32: Atmel AVR32
    AVR32
    The AVR32 is a 32-bit RISC microprocessor architecture designed by Atmel. The microprocessor architecture was designed by a handful of people educated at the Norwegian University of Science and Technology, including lead designer Øyvind Strøm, PhD and CPU architect Erik Renno, M.Sc in Atmel's...

     architecture
  • hppa: HP PA-RISC
    PA-RISC
    PA-RISC is an instruction set architecture developed by Hewlett-Packard. As the name implies, it is a reduced instruction set computer architecture, where the PA stands for Precision Architecture...

     architecture
  • m68k: Motorola 68k architecture on Amiga
    Amiga
    The Amiga is a family of personal computers that was sold by Commodore in the 1980s and 1990s. The first model was launched in 1985 as a high-end home computer and became popular for its graphical, audio and multi-tasking abilities...

    , Atari
    Atari ST
    The Atari ST is a home/personal computer that was released by Atari Corporation in 1985 and commercially available from that summer into the early 1990s. The "ST" officially stands for "Sixteen/Thirty-two", which referred to the Motorola 68000's 16-bit external bus and 32-bit internals...

    , Macintosh
    Macintosh
    The Macintosh , or Mac, is a series of several lines of personal computers designed, developed, and marketed by Apple Inc. The first Macintosh was introduced by Apple's then-chairman Steve Jobs on January 24, 1984; it was the first commercially successful personal computer to feature a mouse and a...

     and various embedded VME
    VMEbus
    VMEbus is a computer bus standard, originally developed for the Motorola 68000 line of CPUs, but later widely used for many applications and standardized by the IEC as ANSI/IEEE 1014-1987. It is physically based on Eurocard sizes, mechanicals and connectors , but uses its own signalling system,...

     systems
  • powerpcspe: PowerPCSPE
    PowerPC e500
    The PowerPC e500 is a 32-bit Power Architecture-based microprocessor core from Freescale Semiconductor. The core is compatible with the older PowerPC Book E specification as well as the Power ISA v.2.03. It has a dual issue, seven-stage pipeline with FPUs , 32/32 KiB data and instruction L1 caches...

     architecture (binary-incompatible variant of the PowerPC
    PowerPC
    PowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...

    )
  • sh4: Hitachi SuperH
    SuperH
    SuperH is a 32-bit reduced instruction set computer instruction set architecture developed by Hitachi. It is implemented by microcontrollers and microprocessors for embedded systems....

     architecture
  • sparc64: Sun SPARC
    SPARC
    SPARC is a RISC instruction set architecture developed by Sun Microsystems and introduced in mid-1987....

     architecture with 64-bit userland


The m68k port was the second official one in Debian, and has been part of five stable Debian releases. Due to its failure to meet the release criteria, it was dropped before the release of etch. The OABI arm as well as alpha and hppa were dropped before the release of squeeze.

Derivatives


Many distributions have chosen to extend Debian based on the different distributions Debian offers.
Distribution Debian distribution branch
Ubuntu
Ubuntu (operating system)
Ubuntu is a computer operating system based on the Debian Linux distribution and distributed as free and open source software. It is named after the Southern African philosophy of Ubuntu...

 
Unstable
Ubuntu
Ubuntu (operating system)
Ubuntu is a computer operating system based on the Debian Linux distribution and distributed as free and open source software. It is named after the Southern African philosophy of Ubuntu...

 (Long term release)
Testing
MEPIS
MEPIS
MEPIS is a set of Linux distributions, distributed as Live CDs that can be installed onto a hard disk drive.MEPIS is developed and maintained by an active community begun by Warren Woodford and the eponymous company MEPIS LLC....

 (SimplyMEPIS)
Stable
MEPIS
MEPIS
MEPIS is a set of Linux distributions, distributed as Live CDs that can be installed onto a hard disk drive.MEPIS is developed and maintained by an active community begun by Warren Woodford and the eponymous company MEPIS LLC....

 (antiX)
Testing
Damn Small Linux
Damn Small Linux
Damn Small Linux or DSL is a computer operating system for the x86 family of personal computers. It is free and open source software under the terms of GNU GPL and other free and open source licenses. It was designed to run graphical applications on older PC hardware—for example, machines with...

 
Unknown
Xandros
Xandros
Xandros is the name of both a line of operating systems and Xandros Corporation, the company which creates them. Xandros Desktop was a Linux distribution. The name Xandros is derived from the X Window System and the Greek island of Andros....

 
Unknown
Knoppix
Knoppix
Knoppix, or KNOPPIX , is an operating system based on Debian designed to be run directly from a CD / DVD or a USB key , one of the first of its kind for any operating system. Knoppix was developed by Linux consultant Klaus Knopper. When starting a program, it is loaded from the removable medium...

 
Unknown
BackTrack
BackTrack
BackTrack is an operating system based on the Ubuntu GNU/Linux distribution aimed at digital forensics and penetration testing use. It is named after backtracking, a search algorithm...

 
Unknown
Linspire
Linspire
Linspire, previously known as LindowsOS, was a commercial operating system based on Debian GNU/Linux and later Ubuntu. Linspire was published by Linspire, Inc. and focused on ease-of-use, targeting home PC users...

 
Unknown
aptosid (former sidux) Unstable
Kanotix
Kanotix
Kanotix, also referred to as KANOTIX, is an operating system Live CD based on Debian, with advanced hardware detection. It can run from an optical disc drive or other media i.e. USB-stick without using a hard disk drive....

 
Stable
Parsix
Parsix
Parsix GNU/Linux is a live and installation DVD based on Debian. The Parsix project's goal is to provide a ready to use, easy to install, desktop and laptop optimized operating system based on Debian's testing branch and the latest stable release of GNOME desktop environment. It is possible to...

 
Testing
LinEx
GnuLinEx
gnuLinEx, or LinEx, is a Debian-based GNU-Linux operating system that uses GNOME for its desktop. An initiative of the regional government of Extremadura, Spain, gnuLinEx is intended to be used in all schools in Extremadura, as well as in official institutions. It is actively promoted for business...

 
Unknown
CrunchBang Linux
CrunchBang Linux
CrunchBang Linux is a lightweight Debian based Linux distribution, created by Philip Newborough, designed to offer a good balance of speed and functionality.- Features :...

 
Stable
Linux Mint
Linux Mint
Linux Mint is a Linux-based computer operating system best known for its usability and ease of installation, particularly for users with no previous GNU/Linux experience...

 (Debian edition)
Testing
Vyatta
Vyatta
Vyatta manufactures an open source router/firewall/VPN product for Internet Protocol networks . A free download of Vyatta has been available since March 2006. The system is a specialized Debian-based Linux distribution with networking applications such as Quagga, OpenVPN, and many others...

 
Unknown
others  Unknown

Reception


Debian was ranked second only to Ubuntu
Ubuntu (operating system)
Ubuntu is a computer operating system based on the Debian Linux distribution and distributed as free and open source software. It is named after the Southern African philosophy of Ubuntu...

 (which is itself derived from Debian) for Most Used Linux Distribution for both Personal and Organizational use in a 2007 survey by SurveyMonkey.com. Debian won the 2007 poll on Server Distribution of the Year by LinuxQuestions.org
LinuxQuestions.org
LinuxQuestions.org is a community-driven, self-help web site for Linux users. As of August 2011, it has over 462,200 registered members...

.

Both the Debian distribution and their website have won various awards from different organizations. Debian was awarded the 2004 Readers' Choice Award for Favorite Linux Distribution by the Linux Journal
Linux Journal
Linux Journal is a monthly technology magazine published by Belltown Media, Inc. of Houston, Texas. The magazine focuses specifically on Linux, allowing the content to be a highly specialized source of information for open source enthusiasts.-History:...

. A total of fifteen other awards have been awarded throughout Debian's lifetime including Best Linux Distribution.

Debian has also received negative assessments. In May 2008, a Debian Developer revealed his discovery that changes made in 2006 to the random number generator
Random number generation
A random number generator ) is a computational or physical device designed to generate a sequence of numbers or symbols that lack any pattern, i.e. appear random....

 in the version of the openSSL
OpenSSL
OpenSSL is an open source implementation of the SSL and TLS protocols. The core library implements the basic cryptographic functions and provides various utility functions...

 package distributed with Debian and other Debian-based distributions such as Ubuntu
Ubuntu (operating system)
Ubuntu is a computer operating system based on the Debian Linux distribution and distributed as free and open source software. It is named after the Southern African philosophy of Ubuntu...

 or Knoppix
Knoppix
Knoppix, or KNOPPIX , is an operating system based on Debian designed to be run directly from a CD / DVD or a USB key , one of the first of its kind for any operating system. Knoppix was developed by Linux consultant Klaus Knopper. When starting a program, it is loaded from the removable medium...

, made a variety of security keys vulnerable to a random number generator attack
Random number generator attack
The security of cryptographic systems depends on some secret data that is known to authorized persons but unknown and unpredictable to others. To achieve this unpredictability, some randomization is typically employed...

. The security weakness was caused by changes made to the openssl code by another Debian Developer in response to memory debugger warnings. The security hole was soon patched by Debian and others, but the complete resolution procedure was cumbersome for users because it involved regenerating all affected keys, and it drew criticism to Debian's practice of making Debian-specific changes to software.

Richard Stallman
Richard Stallman
Richard Matthew Stallman , often shortened to rms,"'Richard Stallman' is just my mundane name; you can call me 'rms'"|last= Stallman|first= Richard|date= N.D.|work=Richard Stallman's homepage...

 and the Free Software Foundation
Free Software Foundation
The Free Software Foundation is a non-profit corporation founded by Richard Stallman on 4 October 1985 to support the free software movement, a copyleft-based movement which aims to promote the universal freedom to create, distribute and modify computer software...

 (FSF) have criticized the Debian Project for providing the non-free repository, rather than excluding this type of software entirely, an opinion also echoed by some in Debian including the then-Project Leader Wichert Akkerman
Wichert Akkerman
Wichert Akkerman is a Dutch computer programmer, best known for his contributions to Debian, dpkg, Plone and strace.He was elected for two terms as the Debian Project Leader and served from January 1999 to March 2001. He was succeeded in that role by Ben Collins...

.The internal dissent in the Debian Project regarding the non-free section has persisted, but the last time it came to a vote in 2006, a large majority decided to keep it.

During the release cycles of Woody and Sarge, the Debian Project drew considerable criticism from the free software community because of the extended period between stable releases. This triggered the creation of Ubuntu
Ubuntu (operating system)
Ubuntu is a computer operating system based on the Debian Linux distribution and distributed as free and open source software. It is named after the Southern African philosophy of Ubuntu...

 in 2004. Ubuntu has releases every 6 months which are forks
Fork (software development)
In software engineering, a project fork happens when developers take a legal copy of source code from one software package and start independent development on it, creating a distinct piece of software...

 of Debian's unstable distribution with bug fixes and other modifications. However, it may be more appropriate to compare Debian releases (which continue to be supported after the release of subsequent versions) to Ubuntu's Long Term Support releases (which are supported for three years for desktops and five years for servers); Ubuntu produces a new LTS release every two years, which is therefore similar to Debian's new two-year release cycle for post-Debian 6.0 releases.

When in need of updated versions of software, it is possible to use Debian testing instead of stable as it usually contains more modern, though slightly less stable packages. Another alternative is to use Debian backports
Backporting
Backporting is the action of taking a certain software modification and applying it to an older version of the software than it was initially created for. It is part of the maintenance step in a software development process....

, which are "recompiled packages from testing (mostly) and unstable (in a few cases only, e.g. security updates), so they will run without new libraries (wherever it is possible) on a stable Debian distribution".

See also



  • Comparison of Linux distributions
    Comparison of Linux distributions
    Technical variations of Linux distributions include support for different hardware devices and systems or software package configurations. Organizational differences may be motivated by historical reasons...

  • DCC Alliance
    DCC Alliance
    The DCC Alliance was an industry association designed to promote a common subset of the Debian GNU/Linux operating system that multiple companies within the consortium could distribute.-History:...

  • Debian Live
    Debian Live
    A Debian Live system is an instance of the Debian operating system which boots from removable media, without requiring installation or previous configuration. Supported removable media include CDs, DVDs, and USB flash drives ....

  • List of Linux distributions

External links