Debian (), also known as Debian GNU/Linux, is a

Linux distribution A Linux distribution (often abbreviated as distro) is an operating system made from a software collection that includes the Linux kernel and, often, a package management system. Linux users usually obtain their operating system by downloading one ...

composed of

free and open-source software Free and open-source software (FOSS) is a term used to refer to groups of software consisting of both free software and open-source software where anyone is freely licensed to use, copy, study, and change the software in any way, and the source ...

, developed by the community-supported Debian Project, which was established by

Ian Murdock Ian Ashley Murdock (April28, 1973 – December 28, 2015) was an American software engineer, known for being the founder of the Debian project and Progeny Linux Systems, a commercial Linux company. Life and career Although Murdock's parents were ...

on August 16, 1993. The first version of Debian (0.01) was released on September 15, 1993, and its first stable version (1.1) was released on June 17, 1996. The Debian Stable

branch A branch, sometimes called a ramus in botany, is a woody structural member connected to the central trunk (botany), trunk of a tree (or sometimes a shrub). Large branches are known as boughs and small branches are known as twigs. The term '' ...

is the most popular edition for

personal computer A personal computer (PC) is a multi-purpose microcomputer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or tec ...

s and servers. Debian is also the basis for many other distributions, most notably

Ubuntu Ubuntu ( ) is a Linux distribution based on Debian and composed mostly of free and open-source software. Ubuntu is officially released in three editions: ''Desktop'', ''Server'', and ''Core'' for Internet of things devices and robots. All the ...

. Debian is one of the oldest operating systems based on the

Linux kernel The Linux kernel is a free and open-source, monolithic, modular, multitasking, Unix-like operating system kernel. It was originally authored in 1991 by Linus Torvalds for his i386-based PC, and it was soon adopted as the kernel for the GNU ope ...

. The project is coordinated over the

Internet The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a '' network of networks'' that consists of private, pub ...

by a team of volunteers guided by the

Debian Project Leader This is a chronological list of Debian project leaders. Debian is a computer operating system composed of software packages released as free and open-source software primarily under the GNU General Public License, developed by a group of individual ...

and three foundational documents: the

Debian Social Contract The Debian Social Contract (DSC) is a document that frames the moral agenda of the Debian project. The values outlined in the Social Contract provide the basic principles for the Debian Free Software Guidelines that serve as the basis of the Open ...

, the Debian Constitution, and the

Debian Free Software Guidelines The Debian Free Software Guidelines (DFSG) 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 Deb ...

. New distributions are updated continually, and the next candidate is released after a time-based freeze. Since its founding, Debian has been developed openly and distributed freely according to the principles of the

GNU Project The GNU Project () is a free software, mass collaboration project announced by Richard Stallman on September 27, 1983. Its goal is to give computer users freedom and control in their use of their computers and computing devices by collaborati ...

. Because of this, the

Free Software Foundation The Free Software Foundation (FSF) is a 501(c)#501(c)(3), 501(c)(3) non-profit organization founded by Richard Stallman on October 4, 1985, to support the free software movement, with the organization's preference for software being distributed ...

sponsored the project from November 1994 to November 1995. When the sponsorship ended, the Debian Project formed the

nonprofit organization A nonprofit organization (NPO) or non-profit organisation, also known as a non-business entity, not-for-profit organization, or nonprofit institution, is a legal entity organized and operated for a collective, public or social benefit, in co ...

Software in the Public Interest Software in the Public Interest, Inc. (SPI) is a US 501(c)(3) non-profit organization domiciled in New York State formed to help other organizations create and distribute free open-source software and open-source hardware. Anyone is eligible to ...

to continue financially supporting development.

History

Debian version history

Debian distribution codenames are based on the names of characters from the ''

Toy Story ''Toy Story'' is a 1995 American computer-animated comedy film directed by John Lasseter (in his feature directorial debut), produced by Pixar Animation Studios and released by Walt Disney Pictures. The first installment in the '' Toy Story ...

'' films. Debian's ''unstable'' trunk is named after Sid, a character who regularly destroyed his toys.

Founding (1993–1998)

Debian was first announced on August 16, 1993, by

, who initially called the system "the Debian Linux Release". The word "Debian" was formed as a

portmanteau A portmanteau word, or portmanteau (, ) is a blend of wordsSoftlanding Linux System Softlanding Linux System (SLS) was one of the first Linux distributions. The first release was by Peter MacDonald in August 1992. Their slogan at the time was "Gentle Touchdowns for DOS Bailouts". SLS was the first release to offer a comprehen ...

(SLS) had been a popular Linux distribution and the basis for

Slackware Slackware is a Linux distribution created by Patrick Volkerding in 1993. Originally based on Softlanding Linux System, Slackware has been the basis for many other Linux distributions, most notably the first versions of SUSE Linux distributions ...

. The perceived poor maintenance and prevalence of bugs in SLS motivated Murdock to launch a new distribution. Debian 0.01, released on September 15, 1993, was the first of several internal releases. Version 0.90 was the first public release, providing support through mailing lists hosted at

Pixar Pixar Animation Studios (commonly known as Pixar () and stylized as P I X A R) is an American computer animation studio known for its critically and commercially successful computer animated feature films. It is based in Emeryville, Californi ...

. The release included the Debian Linux Manifesto, outlining Murdock's view for the new

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...

. In it he called for the creation of a distribution to be maintained "openly in the spirit of Linux and GNU." The Debian project released the 0.9x versions in 1994 and 1995. During this time it was sponsored by the

for one year. Ian Murdock delegated the base system, the core packages of Debian, to Bruce Perens and Murdock focused on the management of the growing project. The first ports to non-

IA-32 IA-32 (short for "Intel Architecture, 32-bit", commonly called i386) is the 32-bit version of the x86 instruction set architecture, designed by Intel and first implemented in the 80386 microprocessor in 1985. IA-32 is the first incarnation of ...

architectures began in 1995, and Debian 1.1 was released in 1996. By that time and thanks to

Ian Jackson Ian Jackson is a longtime free software author and Debian developer. Jackson wrote dpkg (replacing a more primitive Perl tool with the same name), SAUCE (Software Against Unsolicited Commercial Email), userv and debbugs. He used to maintain the ...

, the dpkg package manager was already an essential part of Debian. In 1996,

Bruce Perens Bruce Perens (born around 1958) is an American computer programmer and advocate in the free software movement. He created The Open Source Definition and published the first formal announcement and manifesto of open source. He co-founded the Open ...

assumed the project leadership. Perens was a controversial leader, regarded as authoritarian and strongly attached to Debian. He drafted a

social contract In moral and political philosophy Political philosophy or political theory is the philosophical study of government, addressing questions about the nature, scope, and legitimacy of public agents and institutions and the relationships betw ...

and edited suggestions from a month-long discussion into the Debian Social Contract and the Debian Free Software Guidelines. After the FSF withdrew their sponsorship in the midst of the free software vs. open source debate, Perens initiated the creation of the legal

umbrella organization An umbrella organization is an association of (often related, industry-specific) institutions who work together formally to coordinate activities and/or pool resources. In business, political, and other environments, it provides resources and ofte ...

instead of seeking renewed involvement with the FSF. He led the conversion of the project from a.out to

ELF An elf () is a type of humanoid supernatural being in Germanic mythology and folklore. Elves appear especially in North Germanic mythology. They are subsequently mentioned in Snorri Sturluson's Icelandic Prose Edda. He distinguishes "ligh ...

. He created the

BusyBox BusyBox is a software suite that provides several Unix utilities in a single executable file. It runs in a variety of POSIX environments such as Linux, Android, and FreeBSD, although many of the tools it provides are designed to work with in ...

program to make it possible to run a Debian installer on a single

floppy disk A floppy disk or floppy diskette (casually referred to as a floppy, or a diskette) is an obsolescent type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined w ...

, and wrote a new installer. By the time Debian 1.2 was released, the project had grown to nearly two hundred volunteers. Perens left the project in 1998. Ian Jackson became the leader in 1998. Debian 2.0 introduced the second official port,

m68k The Motorola 68000 series (also known as 680x0, m68000, m68k, or 68k) is a family of 32-bit complex instruction set computer (CISC) microprocessors. During the 1980s and early 1990s, they were popular in personal computers and workstations and w ...

. During this time the first port to a non-Linux kernel,

Debian GNU/Hurd Debian (), also known as Debian GNU/Linux, is a Linux distribution composed of free and open-source software, developed by the community-supported Debian Project, which was established by Ian Murdock on August 16, 1993. The first version of Deb ...

, was started. On December 2, the first Debian Constitution was ratified.

Leader election (1999–2005)

From 1999, the project leader was elected yearly. The

Advanced Packaging Tool Advanced package tool, or APT, is a free-software user interface that works with core libraries to handle the installation and removal of software on Debian, and Debian-based Linux distributions. APT simplifies the process of managing software ...

was deployed with Debian 2.1. The number of applicants was overwhelming and the project established the new member process. The first Debian derivatives, namely Libranet,

Corel Linux Corel Linux, also called Corel LinuxOS, was a Debian-based operating system made by Corel that began beta testing on September 21, 1999 and was released to the public on November 15, 1999. It mainly competed against Windows 98 and Windows 2000 by M ...

and Stormix'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 (DMD) is a severe type of muscular dystrophy that primarily affects boys. Muscle weakness usually begins around the age of four, and worsens quickly. Muscle loss typically occurs first in the thighs and pelvis fol ...

. In late 2000, the project reorganized the archive with new package "pools" and created the ''Testing'' distribution, made up of packages considered stable, to reduce the freeze for the next release. In the same year, developers began holding an annual conference called

DebConf is a software utility for performing system-wide configuration tasks on Unix-like operating systems. It is developed for the Debian Linux distribution, and is closely integrated with Debian's package management system, dpkg. When packages are ...

with talks and workshops for developers and technical users. In May 2001,

Hewlett-Packard The Hewlett-Packard Company, commonly shortened to Hewlett-Packard ( ) or HP, was an American multinational information technology company headquartered in Palo Alto, California. HP developed and provided a wide variety of hardware components ...

announced plans to base its Linux development on Debian. In July 2002, the project released version 3.0, code-named Woody, the first release to include cryptographic software, a free licensed KDE and

internationalization In economics, internationalization or internationalisation is the process of increasing involvement of enterprises in international markets, although there is no agreed definition of internationalization. Internationalization is a crucial strateg ...

. During these last release cycles, the Debian project drew considerable criticism from the free software community because of the long time between stable releases. Some events disturbed the project while working on Sarge, as Debian servers were attacked by fire and hackers. One of the most memorable was the Vancouver prospectus. After a meeting held in

Vancouver Vancouver ( ) is a major city in western Canada, located in the Lower Mainland region of British Columbia. As the List of cities in British Columbia, most populous city in the province, the 2021 Canadian census recorded 662,248 people in the ...

, release manager Steve Langasek announced a plan to reduce the number of supported ports to four in order to shorten future release cycles. There was a large reaction because the proposal looked more like a decision and because such a drop would damage Debian's aim to be "the universal operating system". The first version of the Debian-based

, named "4.10 Warty Warthog", was released on October 20, 2004. Because it was distributed as a free download, it became one of the most popular and successful operating systems with more than "40 million users" according to

Canonical Ltd. Canonical Ltd. is a UK-based privately held computer software company founded and funded by South African entrepreneur Mark Shuttleworth to market commercial support and related services for Ubuntu and related projects. Canonical employs staff ...

However, Murdock was critical of the differences between Ubuntu packages and Debian, stating that it leads to incompatibilities.

Sarge and later releases (2005–present)

The 3.1 Sarge release was made in June 2005. This release updated 73% of the software and included over 9,000 new packages. A new installer with a modular design,

Debian-Installer Debian-Installer is a system installer designed for the Debian Linux distribution. It originally appeared in the Debian release 3.1 (Sarge), released on June 6, 2005, although the first release of a Linux distribution that used it was Skolel ...

, allowed installations with

RAID Raid, RAID or Raids may refer to: Attack * Raid (military), a sudden attack behind the enemy's lines without the intention of holding ground * Corporate raid, a type of hostile takeover in business * Panty raid, a prankish raid by male college ...

XFS XFS is a high-performance 64-bit journaling file system created by Silicon Graphics, Inc (SGI) in 1993. It was the default file system in SGI's IRIX operating system starting with its version 5.3. XFS was ported to the Linux kernel in 2001; as ...

and LVM support, improved hardware detection, made installations easier for novice users, and was translated into almost forty languages. An installation manual and release notes were in ten and fifteen languages respectively. The efforts of

Skolelinux Skolelinux/Debian-Edu is a Linux distribution intended for educational use and a Debian Pure Blend. The free and open source software project was founded in Norway in 2001 and is now being internationally developed. Its name is a direct transla ...

Debian-Med A Debian Pure Blend is a project completely inside of Debian targeting a server or a desktop installation in very broad and general terms. A Debian Pure Blend aims to cover interests of specialised users, who might be children, lawyers, medical st ...

and Debian-Accessibility raised the number of packages that were educational, had a medical affiliation, and ones made for people with disabilities. Iceweasel icon

In 2006, as a result of a much-publicized dispute, Mozilla software was rebranded in Debian, with

Firefox Mozilla Firefox, or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. It uses the Gecko rendering engine to display web pages, which implements current and ...

forked as Iceweasel and

Thunderbird Thunderbird, thunder bird or thunderbirds may refer to: * Thunderbird (mythology), a legendary creature in certain North American indigenous peoples' history and culture * Ford Thunderbird, a car Birds * Dromornithidae, extinct flightless birds ...

as Icedove. The Mozilla Corporation stated that software with unapproved modifications could not be distributed under the Firefox trademark. Two reasons that Debian modifies the Firefox software are to change the non-free artwork and to provide security patches. In February 2016, it was announced that Mozilla and Debian had reached an agreement and Iceweasel would revert to the name Firefox; similar agreement was anticipated for Icedove/Thunderbird. A fund-raising experiment, Dunc-Tank, was created to solve the release cycle problem and release managers were paid to work full-time; in response, unpaid developers slowed down their work and the release was delayed.
Debian 4.0 (Etch) was released in April 2007, featuring the x86-64 port and a graphical installer.
Debian 5.0 (Lenny) was released in February 2009, supporting Marvell's Orion platform and netbooks such as the

Asus Eee PC The ASUS Eee PC is a netbook computer line from Asus, 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 lightweight, Linux-based operating system, solid-state drive (S ...

. The release was dedicated to Thiemo Seufer, a developer who died in a car crash. Debian 6

In July 2009, the policy of time-based development freezes on a two-year cycle was announced. Time-based freezes are intended to blend the predictability of time based releases with Debian's policy of feature based releases, and to reduce overall freeze time. The Squeeze cycle was going to be especially short; however, this initial schedule was abandoned. In September 2010, the backports service became official, providing more recent versions of some software for the stable release. Debian 6.0 (Squeeze) was released in February 2011, featuring Debian GNU/kFreeBSD as a technology preview, along with adding a dependency-based boot system, and moving problematic firmware to the non-free section.
Debian 7.0 (Wheezy) was released in May 2013, featuring multiarch support.
Debian 8.0 (Jessie) was released in April 2015, using

systemd systemd is a software suite that provides an array of system components for Linux operating systems. Its main aim is to unify service configuration and behavior across Linux distributions; Its primary component is a "system and service manager ...

as the new init system.
Debian 9.0 (Stretch) was released in June 2017, with nftables as a replacement for iptables, support for Flatpak apps, and MariaDB as the replacement for MySQL.
Debian 10.0 (Buster) was released in July 2019, adding support for

Secure Boot UEFI (Unified Extensible Firmware Interface) is a set of specifications written by the UEFI Forum. They define the architecture of the platform firmware used for booting and its interface for interaction with the operating system. Examples of ...

and enabling

AppArmor AppArmor ("Application Armor") is a Linux kernel security module that allows the system administrator to restrict programs' capabilities with per-program profiles. Profiles can allow capabilities like network access, raw socket access, and the ...

by default.
Debian 11.0 (Bullseye) was released in August 2021, enabling persistency in the system journal, adding support for driverless scanning, and containing kernel-level support for

exFAT exFAT (Extensible File Allocation Table) is a file system introduced by Microsoft in 2006 and optimized for flash memory such as USB flash drives and SD cards. exFAT was proprietary until 28 August 2019, when Microsoft published its specificati ...

filesystems. Debian is still in development and new packages are uploaded to ''unstable'' every day. Debian used to be released as a very large set of CDs for each architecture, but with the release of Debian 9 (Stretch) in 2017, these have been dropped. Throughout Debian's lifetime, both the Debian distribution and its website have won various awards from different organizations, including ''Server Distribution of the Year'' 2011, ''The best Linux distro of 2011'', and a ''Best of the Net'' award for October 1998. On December 2, 2015,

Microsoft Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washing ...

announced that they would offer Debian GNU/Linux as an endorsed distribution on the Azure cloud platform. Microsoft has also added a user environment to their

Windows 10 Windows 10 is a major release of Microsoft's Windows NT operating system. It is the direct successor to Windows 8.1, which was released nearly two years earlier. It was released to manufacturing on July 15, 2015, and later to retail on J ...

desktop operating system called

Windows Subsystem for Linux Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...

that offers a Debian subset.

Features

Debian has access to online repositories that contain over 51,000

packages Package may refer to: Containers or Enclosures * Packaging and labeling, enclosing or protecting products * Mail, items larger than a letter * Chip package or chip carrier * Electronic packaging, in electrical engineering * Automotive package, ...

. Debian officially contains only free software, but non-free software can be downloaded and installed from the Debian repositories. Debian includes popular free programs such as

LibreOffice LibreOffice () is a free and open-source productivity software, office productivity software suite, a project of The Document Foundation (TDF). It was fork (software development), forked in 2010 from OpenOffice.org, an open-sourced version of t ...

web browser,

Evolution Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...

mail, K3b disc burner,

VLC media player VLC media player (previously the VideoLAN Client and commonly known as simply VLC) is a free and open-source, portable, cross-platform media player software and streaming media server developed by the VideoLAN project. VLC is available for desk ...

GIMP GIMP ( ; GNU Image Manipulation Program) is a free and open-source raster graphics editor used for image manipulation (retouching) and image editing, free-form drawing, transcoding between different image file formats, and more specialized task ...

image editor, and

Evince Evince (), also known as GNOME Document Viewer, is a free and open source document viewer supporting many document file formats including PDF, PostScript, DjVu, TIFF, XPS and DVI. It is designed for the GNOME desktop environment. The develo ...

document viewer. Debian is a popular choice for servers, for example as the operating system component of a

LAMP Lamp, Lamps or LAMP may refer to: Lighting * Oil lamp, using an oil-based fuel source * Kerosene lamp, using kerosene as a fuel * Electric lamp, or light bulb, a replaceable component that produces light from electricity * Light fixture, or li ...

stack.

Kernels

Several flavors of the Linux kernel exist for each port. For example, the i386 port has flavors for IA-32 PCs supporting

Physical Address Extension In computing, Physical Address Extension (PAE), sometimes referred to as Page Address Extension, is a memory management feature for the x86 architecture. PAE was first introduced by Intel in the Pentium Pro, and later by AMD in the Athlon process ...

and

real-time computing Real-time computing (RTC) is the computer science term for hardware and software systems subject to a "real-time constraint", for example from event to system response. Real-time programs must guarantee response within specified time constrai ...

, for older PCs, and for x86-64 PCs. The Linux kernel does not officially contain

firmware In computing, firmware is a specific class of computer software that provides the low-level control for a device's specific hardware. Firmware, such as the BIOS of a personal computer, may contain basic functions of a device, and may provide h ...

lacking source code, although such firmware is available in non-free packages and alternative installation media.

Desktop environments

Debian offers CD and DVD images specifically built for XFCE,

GNOME A gnome is a mythological creature and diminutive spirit in Renaissance magic and alchemy, first introduced by Paracelsus in the 16th century and later adopted by more recent authors including those of modern fantasy literature. Its characte ...

KDE KDE is an international free software community that develops free and open-source software. As a central development hub, it provides tools and resources that allow collaborative work on this kind of software. Well-known products include the ...

MATE Mate may refer to: Science * Mate, one of a pair of animals involved in: ** Mate choice, intersexual selection ** Mating * Multi-antimicrobial extrusion protein, or MATE, an efflux transporter family of proteins Person or title * Friendship ...

Cinnamon Cinnamon is a spice obtained from the inner bark of several tree species from the genus ''Cinnamomum''. Cinnamon is used mainly as an aromatic condiment and flavouring additive in a wide variety of cuisines, sweet and savoury dishes, breakfa ...

LXDE LXDE (abbreviation for Lightweight X11 Desktop Environment) is a free desktop environment with comparatively low resource requirements. This makes it especially suitable for use on older or resource-constrained personal computers such as netb ...

, and

LXQT LXQt is a free and open source lightweight desktop environment. It was formed from the merger of the LXDE and Razor-qt projects. Like its GTK predecessor LXDE, LXQt does not ship or develop its own window manager, instead LXQt lets the user ...

is officially supported, while

support was added with Debian 8.0 Jessie. Less common

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. They work in conjunction ...

s such as Enlightenment, Openbox,

Fluxbox Fluxbox is a stacking window manager for the X Window System, which started as a fork of Blackbox 0.61.1 in 2001, with the same aim to be lightweight. Its user interface has only a taskbar, a pop-up menu accessible by right-clicking on the des ...

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

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. It is designed to emulate NeXTSTEP's GUI as an OpenStep-compatible environment. Window Maker ...

and others are available. The default desktop environment of version 7.0 Wheezy was temporarily switched to Xfce, because GNOME 3 did not fit on the first CD of the set. The default for the version 8.0 Jessie was changed again to Xfce in November 2013, and back to GNOME in September 2014.

Localization

Several parts of Debian are translated into languages other than American English, including package descriptions, configuration messages, documentation and the website. The level of software localization depends on the language, ranging from the highly supported

German German(s) may refer to: * Germany (of or related to) ** Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ge ...

and French to the barely translated Creek and Samoan. The Debian 10 installer is available in 76 languages.

Multimedia support

Multimedia support has been problematic in Debian regarding

codec A codec is a device or computer program that encodes or decodes a data stream or signal. ''Codec'' is a portmanteau of coder/decoder. In electronic communications, an endec is a device that acts as both an encoder and a decoder on a signal or da ...

s threatened by possible patent infringements, lacking source code, or under too restrictive licenses. Even though packages with problems related to their distribution could go into the non-free area, software such as

libdvdcss libdvdcss (or libdvdcss2 in some repositories) is a free and open-source software library for accessing and unscrambling DVDs encrypted with the Content Scramble System (CSS). libdvdcss is part of the VideoLAN project and is used by VLC media p ...

is not hosted at Debian. A notable third party repository exists, formerly named debian-multimedia.org, providing software not present in Debian such as

Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...

codecs, libdvdcss and the

Adobe Flash Player Adobe Flash Player (known in Internet Explorer, Firefox, and Google Chrome as Shockwave Flash) is Software, computer software for viewing multimedia contents, executing rich Internet applications, and streaming media, streaming audio and vide ...

. Even though this repository is maintained by Christian Marillat, a Debian developer, it is not part of the project and is not hosted on a Debian server. The repository provides packages already included in Debian, interfering with the official maintenance. Eventually, project leader Stefano Zacchiroli asked Marillat to either settle an agreement about the packaging or to stop using the "Debian" name. Marillat chose the latter and renamed the repository to deb-multimedia.org. The repository was so popular that the switchover was announced by the official blog of the Debian project.

Distribution

Debian offers DVD and CD

images An image is a visual representation of something. It can be two-dimensional, three-dimensional, or somehow otherwise feed into the visual system to convey information. An image can be an artifact, such as a photograph or other two-dimensiona ...

for installation that can be downloaded using BitTorrent or

jigdo Jigdo (a portmanteau of "Jigsaw" and "download") is a utility typically used for downloading to piece together a large file, most commonly an optical disk image such as a CD, DVD or Blu-ray Disc (BD) image, from many smaller individual constit ...

. Physical discs can also be bought from retailers. The full sets are made up of several discs (the amd64 port consists of 13 DVDs or 84 CDs), but only the first disc is required for installation, as the installer can retrieve software not contained in the first disc image from online repositories. Debian offers different network installation methods. A minimal install of Debian is available via the ''netinst'' CD, whereby Debian is installed with just a base and later added software can be downloaded from the Internet. Another option is to boot the installer from the network. The default bootstrap loader is

GNU GRUB GNU GRUB (short for GNU GRand Unified Bootloader, commonly referred to as GRUB) is a boot loader package from the GNU Project. GRUB is the reference implementation of the Free Software Foundation's Multiboot Specification, which provides a use ...

version 2, though the package name is simply grub, while version 1 was renamed to grub-legacy. This conflicts with (e.g.,

Fedora Linux Fedora Linux is a Linux distribution developed by the Fedora Project. Fedora contains software distributed under various free and open-source licenses and aims to be on the leading edge of open-source technologies. Fedora is the upstream sourc ...

), where grub version 2 is named grub2. The default desktop may be chosen from the DVD boot menu among

KDE Plasma Plasma is a desktop environment by KDE, and can refer to: * KDE Plasma 5 (2014–today) * KDE Plasma 4 (2008–2015) * Plasma Mobile for smartphones * Plasma Bigscreen Plasma Bigscreen is a software project from KDE which contains an interface op ...

, Xfce and

, and from special disc 1 CDs. Debian releases live install images for CDs, DVDs and USB thumb drives, for

and

x86-64 x86-64 (also known as x64, x86_64, AMD64, and Intel 64) is a 64-bit version of the x86 instruction set, first released in 1999. It introduced two new modes of operation, 64-bit mode and compatibility mode, along with a new 4-level paging mod ...

architectures, and with a choice of desktop environments. These ''Debian Live'' images allow users to boot from removable media and run Debian without affecting the contents of their computer. A full install of Debian to the computer's hard drive can be initiated from the live image environment. Personalized images can be built with the live-build tool for discs, USB drives and for

network booting Network booting, shortened netboot, 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 (thin clients) such as pub ...

purposes. Installation images are

hybrid Hybrid may refer to: Science * Hybrid (biology), an offspring resulting from cross-breeding ** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species ** Hybridity, the property of a hybrid plant which is a union of two dif ...

on some architectures and can be used to create a

bootable In computing, booting is the process of starting a computer as initiated via hardware such as a button or by a software command. After it is switched on, a computer's central processing unit (CPU) has no software in its main memory, so some ...

USB drive (

Live USB A live USB is a portable USB-attached external data storage device containing a full operating system that can be booted from. The term is reminiscent of USB flash drives but may encompass an external hard disk drive or solid-state drive, thou ...

Packages

Package management A package manager or package-management system is a collection of software tools that automates the process of installing, upgrading, configuring, and removing computer programs for a computer in a consistent manner. A package manager deals w ...

operations can be performed with different tools available on Debian, from the lowest level command dpkg to graphical front-ends like Synaptic. The recommended standard for administering packages on a Debian system is the apt toolset.

dpkg dpkg is the software at the base of the package management system in the free operating system Debian and its numerous derivatives. dpkg is used to install, remove, and provide information about .deb packages. dpkg (Debian Package) itself is a ...

provides the low-level infrastructure for package management. The dpkg database contains the list of installed software on the current system. The dpkg command tool does not know about repositories. The command can work with local

.deb deb is the format, as well as extension of the software package format for the Debian Linux distribution and its derivatives. Design Debian packages are standard Unix ar archives that include two tar archives. One archive holds the cont ...

package files, and information from the dpkg database.

APT tools

(APT) allows administering an installed Debian system to retrieve and resolve package dependencies from repositories. APT tools share dependency information and cached packages. * The apt command itself is intended as an end user interface and enables some options better suited for interactive usage by default compared to more specialized APT like apt-get and apt-cache explained below. * apt-get and apt-cache are command tools of the standard

apt Apt. is an abbreviation for apartment. Apt may also refer to: Places * Apt Cathedral, a former cathedral, and national monument of France, in the town of Apt in Provence * Apt, Vaucluse, a commune of the Vaucluse département of France * A ...

package. apt-get installs and removes packages, and apt-cache is used for searching packages and displaying package information. *

Aptitude An aptitude is a component of a competence to do a certain kind of work at a certain level. Outstanding aptitude can be considered "talent". Aptitude is inborn potential to perform certain kinds of activities, whether physical or mental, and ...

is a

command line A command-line interpreter or command-line processor uses a command-line interface (CLI) to receive commands from a user in the form of lines of text. This provides a means of setting parameters for the environment, invoking executables and pro ...

tool that also offers a

text-based user interface In computing, text-based user interfaces (TUI) (alternately terminal user interfaces, to reflect a dependence upon the properties of computer terminals and not just text), is a retronym describing a type of user interface (UI) common as an ear ...

. The program comes with enhancements such as better search on package

metadata Metadata is "data that provides information about other data", but not the content of the data, such as the text of a message or the image itself. There are many distinct types of metadata, including: * Descriptive metadata – the descriptive ...

GDebi and other front-ends

GDebi is an APT tool which can be used in command-line and on the GUI. GDebi can install a local .deb file via the command line like the dpkg command, but with access to repositories to resolve dependencies. Other graphical front-ends for APT include Software Center, Synaptic and

Apper Apper (originally named KPackageKit) is a free and open source Linux front-end application for the PackageKit package management service by KDE. Apper also has one main difference compared to the old KPackageKit: Apper can list applications ins ...

GNOME Software GNOME Software is a utility for installing applications and updates on Linux. It is part of the GNOME Core Applications, and was introduced in GNOME 3.10. It is the GNOME front-end to the PackageKit, in turn a front-end to several package manag ...

is a graphical front-end for

PackageKit PackageKit is a free and open-source suite of software applications designed to provide a consistent and high-level front end for a number of different package management systems. PackageKit was created by Richard Hughes in 2007, and first intr ...

, which itself can work on top of various software packaging systems.

Repositories

The

(DFSG) define the distinctive meaning of the word "free" as in "

". Packages that comply with these guidelines, usually under the GNU General Public License,

Modified BSD License BSD licenses are a family of permissive free software licenses, imposing minimal restrictions on the use and distribution of covered software. This is in contrast to copyleft licenses, which have share-alike requirements. The original BSD lice ...

Artistic License Artistic license (alongside more contextually-specific derivative terms such as poetic license, historical license, dramatic license, and narrative license) refers to deviation from fact or form for artistic purposes. It can include the alterat ...

, are included inside the ''main'' area; otherwise, they are included inside the ''non-free'' and ''contrib'' areas. These last two areas are not distributed within the official installation media, but they can be adopted manually. Non-free includes packages that do not comply with the DFSG, such as documentation with invariant sections and

proprietary software Proprietary software is software that is deemed within the free and open-source software to be non-free because its creator, publisher, or other rightsholder or rightsholder partner exercises a legal monopoly afforded by modern copyright and int ...

, and legally questionable packages. Contrib includes packages which do comply with the DFSG but fail other requirements. For example, they may depend on packages which are in non-free or requires such for building them.

Richard Stallman Richard Matthew Stallman (; born March 16, 1953), also known by his initials, rms, is an American free software movement activist and programmer. He campaigns for software to be distributed in such a manner that its users have the freedom to ...

and the

have criticized the Debian project for hosting the non-free repository and because the contrib and non-free areas are easily accessible, an opinion echoed by some in Debian including the former project leader Wichert Akkerman. The internal dissent in the Debian project regarding the non-free section has persisted, but the last time it came to a vote in 2004, the majority decided to keep it.

Cross-distribution package manager

The most popular optional Linux cross-distribution package manager are graphical (front-ends) package managers. They are available within the official Debian Repository but are not installed by default. They are widely popular with both Debian users and Debian software developers who are interested in installing the most recent versions of application or using the cross-distribution package manager built-in sandbox environment. While at the same time remaining in control of the security. Three most popular cross-distribution package managers. Sorted in alphabetical order: *

Flatpak Flatpak, formerly known as xdg-app, is a utility for software deployment and package management for Linux. It is advertised as offering a sandbox environment in which users can run application software in isolation from the rest of the system. ...

software code is owned and maintained by the not for profit Flatpak Team. With an open source LGPL-2.1-only license. * Homebrew software code is owned and maintained by its original author Max Howell. With an open source

BSD 2-Clause License BSD licenses are a family of permissive free software licenses, imposing minimal restrictions on the use and distribution of covered software. This is in contrast to copyleft licenses, which have share-alike requirements. The original BSD lice ...

license. *

Snap Snap or SNAP may refer to: Arts and entertainment * ''Snap'', the original release title for the 2013 film ''Enter the Dangerous Mind'' *''Snap'' (TV series), a CITV programme * ''The Stanly News and Press'', a newspaper in Albemarle, North Carol ...

software code is owned and maintained by the for profit Canonical Group Limited. With an open source GNU General Public License, version 3.0 license.

Branches

Three

branches A branch, sometimes called a ramus in botany, is a woody structural member connected to the central trunk of a tree (or sometimes a shrub). Large branches are known as boughs and small branches are known as twigs. The term ''twig'' usually ...

of Debian (also called ''releases'', ''distributions'' or ''suites'') are regularly maintained: * ''Stable'' is the current release and targets stable and well-tested software needs. ''Stable'' is made by freezing ''Testing'' for a few months where bugs are fixed and packages with too many bugs are removed; then the resulting system is released as ''stable''. It is updated only if major security or usability fixes are incorporated. This branch has an optional backports service that provides more recent versions of some software. ''Stable''s CDs and DVDs can be found in the Debian website. * ''Testing'' is the preview branch that will eventually become the next major release. The packages included in this branch have had some testing in ''unstable'' but they may not be fit for release yet. It contains newer packages than ''stable'' but older than ''unstable''. This branch is updated continually until it is frozen. ''Testing''s CDs and DVDs can be found on the Debian website. * ''Unstable'', always codenamed ''sid'', is the trunk. Packages are accepted without checking the distribution as a whole. This branch is usually run by software developers who participate in a project and need the latest libraries available, and by those who prefer bleeding-edge software. Debian does not provide full Sid installation discs, but rather a minimal ISO that can be used to install over a network connection. Additionally, this branch can be installed through a system upgrade from ''stable'' or ''testing''. Other branches in Debian: * ''Oldstable'' is the prior ''stable'' release. It is supported by the Debian Security Team until one year after a new ''stable'' is released, and since the release of Debian 6, for another 2 years through the Long Term Support project. Eventually, ''oldstable'' is moved to a repository for archived releases. Debian 10 is the current Oldstable release. * ''Oldoldstable'' is the prior ''oldstable'' release. It is supported by the Long Term Support community. Eventually, ''oldoldstable'' is moved to a repository for archived releases. Debian 9 is the current Oldoldstable release. * ''Experimental'' is a temporary staging area of highly experimental software that is likely to break the system. It is not a full distribution and missing dependencies are commonly found in ''unstable'', where new software without the damage chance is normally uploaded. The ''snapshot'' archive provides older versions of the branches. They may be used to install a specific older version of some software.

Numbering scheme

''Stable'' and ''oldstable'' get minor updates, called ''point releases''; , the ''stable'' release is version 11.0, released on , and the ''oldstable'' release is version 10.10. The numbering scheme for the point releases up to Debian 4.0 was to include the letter ''r'' (for ''revision'') after the main version number and then the number of the point release; for example, the latest point release of version 4.0 is 4.0r9. This scheme was chosen because a new dotted version would make the old one look obsolete and vendors would have trouble selling their CDs. From Debian 5.0, the numbering scheme of point releases was changed, conforming to the GNU version numbering standard; the first point release of Debian 5.0 was 5.0.1 instead of 5.0r1. The numbering scheme was once again changed for the first Debian 7 update, which was version 7.1. The ''r'' scheme is no longer in use, but point release announcements include a note about not throwing away old CDs.

Derivatives and flavors

Debian is one of the most popular Linux distributions, and many other distributions have been created from the Debian codebase. ,

DistroWatch DistroWatch is a website which provides news, distribution pages hit rankings, and other general information about various Linux distributions as well as other free software/open source Unix-like operating systems. It now contains information on ...

lists 121 active Debian derivatives. The Debian project provides its derivatives with guidelines for best practices and encourages derivatives to merge their work back into Debian.

Debian Pure Blend A Debian Pure Blend is a project completely inside of Debian targeting a server or a desktop installation in very broad and general terms. A Debian Pure Blend aims to cover interests of specialised users, who might be children, lawyers, medical s ...

s are subsets of a Debian release configured out-of-the-box for users with particular skills and interests. For example, Debian Jr. is made for children, while

Debian Science A Debian Pure Blend is a project completely inside of Debian targeting a server or a desktop installation in very broad and general terms. A Debian Pure Blend aims to cover interests of specialised users, who might be children, lawyers, medical st ...

is for researchers and scientists. The complete Debian distribution includes all available Debian Pure Blends. "Debian Blend" (without "Pure") is a term for a Debian-based distribution that strives to become part of mainstream Debian, and have its extra features included in future releases. Horned logo

Debian GNU/kFreeBSD is a discontinued Debian flavor. It used the

FreeBSD FreeBSD is a free and open-source Unix-like operating system descended from the Berkeley Software Distribution (BSD), which was based on Research Unix. The first version of FreeBSD was released in 1993. In 2005, FreeBSD was the most popular ...

kernel Kernel may refer to: Computing * Kernel (operating system), the central component of most operating systems * Kernel (image processing), a matrix used for image convolution * Compute kernel, in GPGPU programming * Kernel method, in machine learnin ...

and

GNU GNU () is an extensive collection of free software (383 packages as of January 2022), which can be used as an operating system or can be used in parts with other operating systems. The use of the completed GNU tools led to the family of operat ...

userland. The majority of software in Debian GNU/kFreeBSD was built from the same sources as Debian, with some kernel packages from

. The ''k'' in ''kFreeBSD'' is an abbreviation for ''kernel'', which refers to the FreeBSD kernel. Before discontinuing the project, Debian maintained i386 and amd64 ports. The last version of Debian kFreeBSD was Debian 8 (Jessie) RC3. Debian GNU/kFreeBSD was created in 2002. It was included in Debian 6.0 (Squeeze) as a

technology preview A software release life cycle is the sum of the stages of development and maturity for a piece of computer software ranging from its initial development to its eventual release, and including updated versions of the released version to help impro ...

, and in Debian 7.0 (Wheezy) as an official port. Debian GNU/kFreeBSD was discontinued as an officially supported platform as of Debian 8.0. Debian developers cited OSS, pf,

jails A prison, also known as a jail, gaol (dated, standard English, Australian, and historically in Canada), penitentiary (American English and Canadian English), detention center (or detention centre outside the US), correction center, correc ...

, NDIS, and

ZFS ZFS (previously: Zettabyte File System) is a file system with volume management capabilities. It began as part of the Sun Microsystems Solaris operating system in 2001. Large parts of Solaris – including ZFS – were published under an ope ...

as reasons for being interested in the FreeBSD kernel. It has not been updated since Debian 8. As of July 2019, however, the operating system continues to be maintained unofficially.

Debian GNU/Hurd is a flavor based on the

Hurd GNU Hurd is a collection of microkernel servers written as part of GNU, for the GNU Mach microkernel. It has been under development since 1990 by the GNU Project of the Free Software Foundation, designed as a replacement for the Unix kernel, an ...

microkernel In computer science, a microkernel (often abbreviated as μ-kernel) is the near-minimum amount of software that can provide the mechanisms needed to implement an operating system (OS). These mechanisms include low-level address space management, ...

, instead of Linux. Debian GNU/Hurd has been in development since 1998, and made a formal release in May 2013, with 78% of the software packaged for Debian GNU/Linux ported to the GNU Hurd. Hurd is not yet an official Debian release, and is maintained and developed as an unofficial port. Debian GNU/Hurd is distributed as an installer CD (running the official Debian installer) or ready-to-run

virtual disk image A disk image, in computing, is a computer file containing the contents and structure of a disk volume or of an entire data storage device, such as a hard disk drive, tape drive, floppy disk, optical disc, or USB flash drive. A disk image is usua ...

(

Live CD A live CD (also live DVD, live disc, or live operating system) is a complete bootable computer installation including operating system which runs directly from a CD-ROM or similar storage device into a computer's memory, rather than loading fro ...

). The CD uses the

architecture, making it compatible with

and

PCs. The current version of Debian GNU/Hurd is 2021, published in August 2021.

Branding

The Debian "swirl" logo was designed by Raul Silva in 1999 as part of a contest to replace the semi-official logo that had been used. The winner of the contest received an @debian.org

email address An email address identifies an email box to which messages are delivered. While early messaging systems used a variety of formats for addressing, today, email addresses follow a set of specific rules originally standardized by the Internet Engineer ...

, and a set of Debian 2.1 install CDs for the architecture of their choice. There has been no official statement from the Debian project on the logo's meaning, but at the time of the logo's selection, it was suggested that the logo represented the

magic smoke Magic smoke (also factory smoke, blue smoke, or the genie) is a humorous name for the caustic smoke produced by severe electrical over-stress of electronic circuits or components, causing overheating and an accompanying release of smoke. The sm ...

or the genie
) that made computers work. One theory about the origin of the Debian logo is that

Buzz Lightyear Buzz Lightyear is the main character in the ''Toy Story'' franchise created by Disney and Pixar mainly voiced by Tim Allen. He is a Superhero toy action figure based on the in-universe media franchise consisting of a blockbuster feature fi ...

, the chosen character for the first named Debian release, has a swirl in his chin.

Stefano Zacchiroli Stefano Zacchiroli is an Italian and French academic and computer scientist who lives and works in Paris, and a former Debian Project Leader. Debian involvement Zacchiroli became a Debian Developer in 2001. After attending LinuxTag in 2004, he ...

also suggested that this swirl is the Debian one. Buzz Lightyear's swirl is a more likely candidate as the codenames for Debian are names of Toy Story characters. The former Debian project leader

used to work for Pixar and is credited as a studio tools engineer on ''

Toy Story 2 ''Toy Story 2'' is a 1999 American computer-animated film produced by Pixar Animation Studios for Walt Disney Pictures. The second installment in the Toy Story (franchise), ''Toy Story'' franchise and the sequel to ''Toy Story'' (1995), it wa ...

'' (1999).

Hardware

Hardware requirements are at least those of the kernel and the

toolsets. Debian's recommended system requirements depend on the level of installation, which corresponds to increased numbers of installed components: The real minimum memory requirements depend on the architecture and may be much less than the numbers listed in this table. It is possible to install Debian with 170 MB of RAM for x86-64; the installer will run in low memory mode and it is recommended to create a

swap partition In computer operating systems, memory paging is a memory management scheme by which a computer stores and retrieves data from secondary storage for use in main memory. In this scheme, the operating system retrieves data from secondary stora ...

. The installer for

z/Architecture z/Architecture, initially and briefly called ESA Modal Extensions (ESAME), is IBM's 64-bit complex instruction set computer (CISC) instruction set architecture, implemented by its mainframe computers. IBM introduced its first z/Architecture-b ...

requires about 20 MB of RAM, but relies on network hardware. Similarly, disk space requirements, which depend on the packages to be installed, can be reduced by manually selecting the packages needed. , no Pure Blend exists that would lower the hardware requirements easily. It is possible to run

graphical user interface The GUI ( "UI" by itself is still usually pronounced . or ), graphical user interface, is a form of user interface that allows users to interact with electronic devices through graphical icons and audio indicator such as primary notation, inste ...

s on older or low-end systems, but the installation of

s instead of

desktop environment In computing, a desktop environment (DE) is an implementation of the desktop metaphor made of a bundle of programs running on top of a computer operating system that share a common graphical user interface (GUI), sometimes described as a graphica ...

s is recommended, as desktop environments are more resource intensive. Requirements for individual software vary widely and must be considered, with those of the base operating environment.

Architectures

, the official ports are: * amd64:

architecture with 64-bit userland and supporting 32-bit software * arm64: ARMv8-A architecture * armel: Little- endian

ARM architecture ARM (stylised in lowercase as arm, formerly an acronym for Advanced RISC Machines and originally Acorn RISC Machine) is a family of reduced instruction set computer (RISC) instruction set architectures for computer processors, configured ...

(ARMv4T instruction set) on various embedded systems (embedded

application binary interface In computer software, an application binary interface (ABI) is an interface between two binary program modules. Often, one of these modules is a library or operating system facility, and the other is a program that is being run by a user. An ' ...

(EABI)), although support has ended after Buster * armhf: ARM hard-float architecture (ARMv7 instruction set) requiring hardware with a

floating-point unit In computing, floating-point arithmetic (FP) is arithmetic that represents real numbers approximately, using an integer with a fixed precision, called the significand, scaled by an integer exponent of a fixed base. For example, 12.345 can b ...

* i386:

architecture with 32-bit userland, compatible with x86-64 machines * mips64el: Little-endian 64-bit MIPS * mipsel: Little-endian 32-bit MIPS * ppc64el: Little-endian

PowerPC PowerPC (with the backronym Performance Optimization With Enhanced RISC – Performance Computing, sometimes abbreviated as PPC) is a reduced instruction set computer (RISC) instruction set architecture (ISA) created by the 1991 Apple Inc., App ...

architecture supporting

POWER7 POWER7 is a family of superscalar multi-core microprocessors based on the Power ISA 2.06 instruction set architecture released in 2010 that succeeded the POWER6 and POWER6+. POWER7 was developed by IBM at several sites including IBM's Roche ...

+ and

POWER8 POWER8 is a family of superscalar multi-core microprocessors based on the Power ISA, announced in August 2013 at the Hot Chips conference. The designs are available for licensing under the OpenPOWER Foundation, which is the first time for s ...

CPUs * s390x: z/Architecture with 64-bit userland, intended to replace s390 Unofficial ports are available as part of the ''unstable'' distribution: * alpha:

DEC Alpha Alpha (original name Alpha AXP) is a 64-bit reduced instruction set computer (RISC) instruction set architecture (ISA) developed by Digital Equipment Corporation (DEC). Alpha was designed to replace 32-bit VAX complex instruction set computers ...

architecture * hppa: HP

PA-RISC PA-RISC is an instruction set architecture (ISA) developed by Hewlett-Packard. As the name implies, it is a reduced instruction set computer (RISC) architecture, where the PA stands for Precision Architecture. The design is also referred to as ...

architecture * hurd-i386:

GNU Hurd GNU Hurd is a collection of microkernel servers written as part of GNU, for the GNU Mach microkernel. It has been under development since 1990 by the GNU Project of the Free Software Foundation, designed as a replacement for the Unix kernel, and ...

kernel on

architecture * ia64:

Intel Itanium Itanium ( ) is a discontinued family of 64-bit Intel microprocessors that implement the Intel Itanium architecture (formerly called IA-64). Launched in June 2001, Intel marketed the processors for enterprise servers and high-performance comput ...

* kfreebsd-amd64: Kernel of

on x86-64 architecture * kfreebsd-i386: Kernel of FreeBSD on IA-32 architecture * m68k:

Motorola 68k The Motorola 68000 series (also known as 680x0, m68000, m68k, or 68k) is a family of 32-bit complex instruction set computer (CISC) microprocessors. During the 1980s and early 1990s, they were popular in personal computers and workstations and w ...

architecture on

Amiga Amiga is a family of personal computers introduced by Commodore in 1985. The original model is one of a number of mid-1980s computers with 16- or 32-bit processors, 256 KB or more of RAM, mouse-based GUIs, and significantly improved graphi ...

Atari Atari () is a brand name that has been owned by several entities since its inception in 1972. It is currently owned by French publisher Atari SA through a subsidiary named Atari Interactive. The original Atari, Inc. (1972–1992), Atari, Inc., ...

Macintosh The Mac (known as Macintosh until 1999) is a family of personal computers designed and marketed by Apple Inc., Apple Inc. Macs are known for their ease of use and minimalist designs, and are popular among students, creative professionals, and ...

and various embedded VME systems * powerpc: 32-bit PowerPC * ppc64: PowerPC64 architecture supporting 64-bit PowerPC CPUs with VMX * riscv64: 64-bit

RISC-V RISC-V (pronounced "risk-five" where five refers to the number of generations of RISC architecture that were developed at the University of California, Berkeley since 1981) is an open standard instruction set architecture (ISA) based on estab ...

* sh4: Hitachi

SuperH SuperH (or SH) is a 32-bit reduced instruction set computing (RISC) instruction set architecture (ISA) developed by Hitachi and currently produced by Renesas. It is implemented by microcontrollers and microprocessors for embedded systems. At t ...

architecture * sparc64: Sun

SPARC SPARC (Scalable Processor Architecture) is a reduced instruction set computer (RISC) instruction set architecture originally developed by Sun Microsystems. Its design was strongly influenced by the experimental Berkeley RISC system developed ...

architecture with 64-bit userland * x32:

x32 ABI The x32 ABI is an application binary interface (ABI) and one of the interfaces of the Linux kernel. The x32 ABI provides 32-bit integers, long and pointers (ILP32) on Intel and AMD 64-bit hardware. The ABI allows programs to take advantage of the b ...

userland for x86-64 Debian supports a variety of

ARM In human anatomy, the arm refers to the upper limb in common usage, although academically the term specifically means the upper arm between the glenohumeral joint (shoulder joint) and the elbow joint. The distal part of the upper limb between th ...

-based

NAS Nas (born 1973) is the stage name of American rapper Nasir Jones. Nas, NaS, or NAS may also refer to: Aviation * Nasair, a low-cost airline carrier and subsidiary based in Eritrea * National Air Services, an airline in Saudi Arabia ** Nas Air ( ...

devices. The

NSLU2 The NSLU2 (Network Storage Link for USB 2.0 Disk Drives) is a network-attached storage (NAS) 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 pro ...

was supported by the installer in Debian 4.0 and 5.0, and

Martin Michlmayr Martin Michlmayr is a free and open-source software advocate and Debian developer, formerly president of Software in the Public Interest. Michlmayr joined the Debian project in 2000. In 2003, Michlmayr was elected as Debian Project Leader; he was ...

is providing installation tarballs since version 6.0. Other supported NAS devices are the Buffalo Kurobox Pro, GLAN Tank, Thecus N2100 and QNAP Turbo Stations. Devices based on the Kirkwood

system on a chip A system on a chip or system-on-chip (SoC ; pl. ''SoCs'' ) is an integrated circuit that integrates most or all components of a computer or other electronic system. These components almost always include a central processing unit (CPU), memory ...

(SoC) are supported too, such as the

SheevaPlug The SheevaPlug is a "plug computer" designed to allow standard computing features in as small a space as possible. As one of the first such computers on the market, the device has a 1.2 GHz Marvell Technology Group, Marvell Kirkwood 6281 AR ...

plug computer and OpenRD products. There are efforts to run Debian on mobile devices, but this is not a project goal yet since the Debian Linux kernel maintainers would not apply the needed patches. Nevertheless, there are packages for resource-limited systems. There are efforts to support Debian on

wireless access point In computer networking, a wireless access point (WAP), or more generally just access point (AP), is a networking hardware device that allows other Wi-Fi devices to connect to a wired network. As a standalone device, the AP may have a wired co ...

s. Debian is known to run on set-top boxes. Work is ongoing to support the AM335x processor, which is used in electronic point of service solutions. Debian may be customized to run on cash machines.

BeagleBoard The BeagleBoard is a low-power open-source single-board computer produced by Texas Instruments in association with Digi-Key and Newark element14. The BeagleBoard was also designed with open source software development in mind, and as a way of de ...

, a low-power

open-source hardware Open-source hardware (OSH) consists of physical artifacts of technology designed and offered by the open-design movement. Both free and open-source software (FOSS) and open-source hardware are created by this open-source culture movement and a ...

single-board computer (made by Texas Instruments) has switched to Debian Linux preloaded on its Beaglebone Black board's flash. Roqos Core, manufactured by Roqos, is a x86-64 based IPS firewall router running Debian Linux.

Organization

Debian's policies and team efforts focus on collaborative software development and testing processes. As a result, a new major release tends to occur every two years with revision releases that fix security issues and important problems. The Debian project is a volunteer organization with three foundational documents: * The ''

'' defines a set of basic principles by which the project and its developers conduct affairs. * The ''

'' define the criteria for "free software" and thus what software is permissible in the distribution. These guidelines have been adopted as the basis of the

Open Source Definition ''The Open Source Definition'' is a document published by the Open Source Initiative, to determine whether a software license can be labeled with the open-source certification mark. The definition was taken from the exact text of the Debian Free ...

. Although this document can be considered separate, 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 Project Leader, the Secretary and other roles. Debian developers are organized in a

web of trust In cryptography, a web of trust is a concept used in PGP, GnuPG, and other OpenPGP-compatible systems to establish the authenticity of the binding between a public key and its owner. Its decentralized trust model is an alternative to the centr ...

. There are about one thousand active Debian developers, but it is possible to contribute to the project without being an official developer. The project maintains official

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 re ...

s and conferences for communication and coordination between developers. For issues with single packages and other tasks, a public bug tracking system is used by developers and end users.

Internet Relay Chat Internet Relay Chat (IRC) is a text-based chat system for instant messaging. IRC is designed for group communication in discussion forums, called ''channels'', but also allows one-on-one communication via private messages as well as chat and ...

is also used for communication among developers and to provide real time help. Debian is supported by donations made to organizations authorized by the leader. The largest supporter is

, the owner of the Debian trademark, manager of the monetary donations and

for various other community free software projects. A Project Leader is elected once per year by the developers. The leader has special powers, but they are not absolute, and appoints delegates to perform specialized tasks. Delegates make decisions as they think is best, taking into account technical criteria and consensus. By way of a General Resolution, the developers may recall the leader, reverse a decision made by the leader or a delegate, amend foundational documents and make other binding decisions. The voting method is based on the

Schulze method The Schulze method () is an electoral 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. The Schulze method is also known a ...

(Cloneproof Schwartz Sequential Dropping). Project leadership is distributed occasionally. Branden Robinson was helped by the Project

Scud A Scud missile is one of a series of tactical ballistic missiles developed by the Soviet Union during the Cold War. It was exported widely to both Second World, Second and Third World, Third World countries. The term comes from the NATO reporti ...

, a team of developers that assisted the leader, but there were concerns that such leadership would split Debian into two developer classes. Anthony Towns created a supplemental position, Second In Charge (2IC), that shared some powers of the leader. Steve McIntyre was 2IC and had a 2IC himself. One important role in Debian's leadership is that of a

release Release may refer to: * Art release, the public distribution of an artistic production, such as a film, album, or song * Legal release, a legal instrument * News release, a communication directed at the news media * Release (ISUP), a code to ident ...

manager. The release team sets goals for the next release, supervises the processes and decides when to release. The team is led by the next release managers and stable release managers. Release assistants were introduced in 2003.

Developers

The Debian Project has an influx of applicants wishing to become developers. These applicants must undergo a vetting process which establishes their identity, motivation, understanding of the project's principles, and technical competence. This process has become much harder throughout the years. Debian developers join the project for many reasons. Some that have been cited include: * Debian is their main operating system and they want to promote Debian * To improve the support for their favorite technology * They are involved with a Debian derivative * A desire to contribute back to the free-software community * To make their Debian maintenance work easier Debian developers may resign their positions at any time or, when deemed necessary, they can be expelled. Those who follow the retiring protocol are granted the "emeritus" status and they may regain their membership through a shortened new member process.

Development

Flowchart of the life cycle of a Debian package

Each software package has a ''maintainer'' that may be either one person or a team of Debian developers and non-developer maintainers. The maintainer keeps track of

upstream Upstream may refer to: * Upstream (bioprocess) * ''Upstream'' (film), a 1927 film by John Ford * Upstream (networking) * ''Upstream'' (newspaper), a newspaper covering the oil and gas industry * Upstream (petroleum industry) * Upstream (software ...

releases, and ensures that the package coheres with the rest of the distribution and meets the standards of quality of Debian. Packages may include modifications introduced by Debian to achieve compliance with Debian Policy, even to fix non-Debian specific bugs, although coordination with upstream developers is advised. The maintainer releases a new version by uploading the package to the "incoming" system, which verifies the integrity of the packages and their

digital signature A digital signature is a mathematical scheme for verifying the authenticity of digital messages or documents. A valid digital signature, where the prerequisites are satisfied, gives a recipient very high confidence that the message was created b ...

s. If the package is found to be valid, it is installed in the package archive into an area called the "pool" and distributed every day to hundreds of

mirrors A mirror or looking glass is an object that Reflection (physics), reflects an image. Light that bounces off a mirror will show an image of whatever is in front of it, when focused through the lens of the eye or a camera. Mirrors reverse the ...

worldwide. The upload must be signed using

OpenPGP Pretty Good Privacy (PGP) is an encryption program that provides cryptographic privacy and authentication for data communication. PGP is used for signing, encrypting, and decrypting texts, e-mails, files, directories, and whole disk partitio ...

-compatible software. All Debian developers have individual cryptographic key pairs. Developers are responsible for any package they upload even if the packaging was prepared by another contributor. Initially, an accepted package is only available in the ''unstable'' branch. For a package to become a candidate for the next release, it must migrate to the ''Testing'' branch by meeting the following: * It has been in ''unstable'' for a certain length of time that depends on the urgency of the changes. * It does not have "release-critical" bugs, except for the ones already present in ''Testing''. Release-critical bugs are those considered serious enough that they make the package unsuitable for release. * There are no outdated versions in ''unstable'' for any release ports. * The migration does not break any packages in ''Testing''. * Its dependencies can be satisfied by packages already in ''Testing'' or by packages being migrated at the same time. * The migration is not blocked by a freeze. Thus, a release-critical bug in a new version of a shared library on which many packages depend may prevent those packages from entering ''Testing'', because the updated library must meet the requirements too. From the branch viewpoint, the migration process happens twice per day, rendering ''Testing'' in

perpetual beta Perpetual beta is the keeping of software or a system at the beta development stage for an extended or indefinite period of time. It is often used by developers when they continue to release new features that might not be fully tested. Perpetual b ...

. Periodically, the release team publishes guidelines to the developers in order to ready the release. A new release occurs after a freeze, when all important software is reasonably up-to-date in the ''Testing'' branch and any other significant issues are solved. At that time, all packages in the ''testing'' branch become the new ''stable'' branch. Although freeze dates are time-based, release dates are not, which are announced by the release managers a couple of weeks beforehand. A version of a package can belong to more than one branch, usually ''testing'' and ''unstable''. It is possible for a package to keep the same version between stable releases and be part of ''oldstable'', ''stable'', ''testing'' and ''unstable'' at the same time. Each branch can be seen as a collection of pointers into the package "pool" mentioned above. One way to resolve the challenge of a release-critical bug in a new application version is the use of optional package managers. They allow software developers to use sandbox environments, while at the same time remaining in control of security. Another benefit of a cross-distribution package manager is that they allow application developers to directly provide updates to users without going through distributions, and without having to package and test the application separately for each distribution.

Release cycle

A new ''stable'' branch of Debian gets released approximately every 2 years. It will receive official support for about 3 years with update for major security or usability fixes. Point releases will be available every several months as determined by Stable Release Managers (SRM). Debian also launched its Long Term Support (LTS) project since Debian 6 (Debian Squeeze). For each Debian release, it will receive two years of extra security updates provided by LTS Team after its End Of Life (EOL). However, no point releases will be made. Now each Debian release can receive 5 years of security support in total.

Security

The Debian project handles security through

public disclosure A public disclosure is any non-Confidentiality, confidential communication which an inventor or invention owner makes to one or more members of the public, revealing the existence of the invention and enabling an appropriately experienced individual ...

. Debian security advisories are compatible with the

Common Vulnerabilities and Exposures The Common Vulnerabilities and Exposures (CVE) system provides a reference-method for publicly known information-security vulnerabilities and exposures. The United States' National Cybersecurity FFRDC, operated by The MITRE Corporation, maintai ...

dictionary, are usually coordinated with other free software vendors and are published the same day a vulnerability is made public. There used to be a security audit project that focused on packages in the stable release looking for security bugs; Steve Kemp, who started the project, retired in 2011 but resumed his activities and applied to rejoin in 2014. The ''stable'' branch is supported by the Debian security team; ''oldstable'' is supported for one year. Although Squeeze is not officially supported, Debian is coordinating an effort to provide

long-term support Long-term support (LTS) is a product lifecycle management policy in which a stable release of computer software is maintained for a longer period of time than the standard edition. The term is typically reserved for open-source software, where i ...

(LTS) until February 2016, five years after the initial release, but only for the IA-32 and x86-64 platforms. ''Testing'' is supported by the ''testing'' security team, but does not receive updates in as timely a manner as ''stable''. ''Unstable''s security is left for the package maintainers. The Debian project offers documentation and tools to harden a Debian installation both manually and automatically.

support is available and enabled by default since Buster. Debian provides an optional hardening wrapper, and does not harden all of its software by default using gcc features such as

PIE A pie is a baked dish which is usually made of a pastry dough casing that contains a filling of various sweet or savoury ingredients. Sweet pies may be filled with fruit (as in an apple pie), nuts ( pecan pie), brown sugar ( sugar pie), swe ...

and

buffer overflow protection Buffer overflow protection is any of various techniques used during software development to enhance the security of executable programs by detecting buffer overflows on stack-allocated variables, and preventing them from causing program misbehavior ...

, unlike operating systems such as

OpenBSD OpenBSD is a security-focused, free and open-source, Unix-like operating system based on the Berkeley Software Distribution (BSD). Theo de Raadt created OpenBSD in 1995 by forking NetBSD 1.0. According to the website, the OpenBSD project em ...

, but tries to build as many packages as possible with hardening flags. In May 2008, a Debian developer discovered that the

OpenSSL OpenSSL is a software library for applications that provide secure communications over computer networks against eavesdropping or need to identify the party at the other end. It is widely used by Internet servers, including the majority of HTT ...

package distributed with Debian and derivatives such as

made a variety of security keys vulnerable to a

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. Modern cryptographic protoco ...

, since only 32,767 different keys were generated. The security weakness was caused by changes made in 2006 by another Debian developer in response to memory debugger warnings. The complete resolution procedure was cumbersome because patching the security hole was not enough; it involved regenerating all affected keys and certificates.

Value

The cost of developing all of the packages included in Debian 5.0 Lenny (323 million lines of code) has been estimated to be about , using one method based on the

COCOMO The Constructive Cost Model (COCOMO) is a procedural software cost estimation model developed by Barry W. Boehm. The model parameters are derived from fitting a regression formula using data from historical projects (63 projects for COCOMO 81 ...

model.Amor, J. J.; Robles, G.; González-Barahona, J. M.; Rivas, F.
Measuring Lenny: the size of Debian 5.0
ResearchGate , Black Duck

Open Hub Black Duck Open Hub, formerly Ohloh, is a website which provides a web services suite and online community platform that aims to index the open-source software development community. It was founded by former Microsoft managers Jason Allen and Sc ...

estimates that the current

codebase In software development, a codebase (or code base) is a collection of source code used to build a particular software system, application, or software component. Typically, a codebase includes only human-written source code files; thus, a codeb ...

(74 million lines of code) would cost about to develop, using a different method based on the same model.

Forks and derivatives

A large number of

forks In cutlery or kitchenware, a fork (from la, furca 'pitchfork') is a utensil, now usually made of metal, whose long handle terminates in a head that branches into several narrow and often slightly curved tines with which one can spear foods ei ...

and derivatives have been built upon Debian over the years. Among the more notable are

, developed by

and first released in 2004, which has surpassed Debian in popularity with desktop users; Knoppix, first released in the year 2000 and one of the first distributions optimized to boot from external storage; and

Devuan Devuan is a fork of the Debian Linux distribution that uses sysvinit, runit or OpenRC instead of systemd. Devuan aims to avoid "lock-in" by projects like systemd and aims to maintain compatibility with other init systems to avoid detaching ...

, which gained attention in 2014 when it forked in disagreement over Debian's adoption of the

software suite, and has been mirroring Debian releases since 2017.

Notes

References

External links

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Debian vs Arch Linux
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TechiWiki
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