======================================================================
= Debian =
======================================================================
Introduction
======================================================================
Debian (), also known as Debian GNU/Linux, is a Linux distribution
composed of free and open-source software and optionally non-free
firmware or software developed by the community-supported Debian
Project, which was established by Ian Murdock 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 is the most popular edition for personal
computers and servers.
Debian is also the basis for many other distributions that have
different purposes, like Proxmox for servers, Ubuntu or Linux Mint for
desktops, Kali for penetration testing, and Pardus and Astra for
government use.
Debian is one of the oldest operating systems based on the Linux
kernel and, as of September 2023, the second oldest Linux distribution
still in active development, only behind Slackware. The project is
coordinated over the Internet by a team of volunteers guided by the
Debian Project Leader and three foundational documents: the Debian
Social Contract, the Debian Constitution, and the Debian Free Software
Guidelines. New distributions are updated continually, and the next
candidate is released after a time-based freeze.
In general, Debian has been developed openly and distributed freely
according to some of the principles of the GNU Project and Free
Software. Because of this, the Free Software Foundation sponsored the
project from November 1994 to November 1995. However, it is no longer
endorsed by GNU and the FSF due to the distribution's long-term
practice of hosting non-free software repositories and, since 2022,
its inclusion of non-free firmware in its installation media by
default. On June 16, 1997, the Debian Project founded the nonprofit
organization Software in the Public Interest to continue financially
supporting development.
Debian version history
========================
Debian distribution codenames are based on the names of characters
from the 'Toy Story' films. Debian's 'unstable' trunk is named after
Sid, a character who regularly destroyed his toys.
Founding (1993–1998)
======================
First announced on August 16, 1993, Debian was founded by Ian Murdock,
who initially called the system "the Debian Linux Release". The word
"Debian" was formed as a portmanteau of the first name of his
then-girlfriend (later ex-wife) Debra Lynn and his own first name.
Before Debian's release, the Softlanding Linux System (SLS) had been a
popular Linux distribution and the basis for Slackware. 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. The release
included the Debian Linux Manifesto, outlining Murdock's view for the
new operating system. 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 Free Software Foundation 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 architectures began in
1995, and Debian 1.1 was released in 1996. By that time and thanks to
Ian Jackson, the dpkg package manager was already an essential part of
Debian.
In 1996, Bruce Perens assumed the project leadership. Perens was a
controversial leader, regarded as authoritarian and strongly attached
to Debian. He drafted a social contract 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 Software in
the Public Interest instead of seeking renewed involvement with the
FSF. He led the conversion of the project from a.out to ELF. He
created the BusyBox program to make it possible to run a Debian
installer on a single floppy disk, 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. During this time the first port to a
non-Linux kernel, Debian GNU/Hurd, 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 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 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.
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 with talks and workshops for developers and technical users.
In May 2001, Hewlett-Packard 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. 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,
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 Ubuntu, 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. 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, allowed installations with
RAID, XFS 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,
Debian-Med and Debian-Accessibility raised the number of packages that
were educational, had a medical affiliation, and ones made for people
with disabilities.
In 2006, as a result of a much-publicized dispute, Mozilla software
was rebranded in Debian, with Firefox forked as Iceweasel and
Thunderbird as Icedove. The Mozilla Corporation stated that software
with unapproved modifications could not be distributed under the
Firefox trademark. Two reasons that Debian modified the Firefox
software were to change 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 release was
dedicated to Thiemo Seufer, a developer who died in a car crash.
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 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 and enabling AppArmor 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 filesystems.
Debian 12.0 (Bookworm) was released on June 10, 2023, including
various improvements and features, increasing the supported Linux
Kernel to version 6.1, and leveraging new "Emerald" artwork.
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, many
of the images have been dropped from the archive but remain buildable
via jigdo.
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 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
desktop operating system called Windows Subsystem for Linux that
offers a Debian subset.
Features
======================================================================
Debian has access to online repositories that contain over 51,000
packages. 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, Firefox web
browser, Evolution mail, K3b disc burner, VLC media player, GIMP image
editor, and Evince document viewer. Debian is a popular choice for
servers, for example as the operating system component of a LAMP
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 and real-time computing, for older PCs, and for x86-64 PCs.
The Linux kernel does not officially contain firmware 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,
KDE, MATE, Cinnamon, LXDE, and LXQt. MATE support was added in 2014,
and Cinnamon support was added with Debian 8.0 Jessie. Less common
window managers such as Enlightenment, Openbox, Fluxbox, IceWM, 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 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 codecs
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 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 codecs, libdvdcss and the Adobe Flash Player. 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{{anchor|Live_images}}
======================================================================
Debian offers DVD and CD images for installation that can be
downloaded using BitTorrent or jigdo. 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 version 2, though the package
name is simply grub, while version 1 was renamed to grub-legacy. This
conflicts with distros (e.g., Fedora Linux), where grub version 2 is
named grub2.
The default desktop may be chosen from the DVD boot menu among GNOME,
KDE Plasma, Xfce and LXDE, and from special disc 1 CDs.
Debian releases live install images for CDs, DVDs and USB thumb
drives, for IA-32 and x86-64 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 purposes. Installation images are hybrid on some
architectures and can be used to create a bootable USB drive (Live
USB).
Packages
======================================================================
Package management 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 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 package files, and information from
the dpkg database.
APT tools
===========
An Advanced Packaging Tool (APT) allows a 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 package.
apt-get installs and removes packages, and apt-cache is used for
searching packages and displaying package information.
* Aptitude is a command line tool that also offers a text-based user
interface. The program comes with enhancements such as better search
on package metadata.
{{Anchor|GDEBI}}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.
GNOME Software is a graphical front-end for PackageKit, which itself
can work on top of various software packaging systems.
Repositories
==============
The Debian Free Software Guidelines (DFSG) define the distinctive
meaning of the word "free" as in "free and open-source software".
Packages that comply with these guidelines, usually under the GNU
General Public License, Modified BSD License or Artistic License, 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, 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 and the Free Software Foundation 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.
Four most popular cross-distribution package managers, sorted in
alphabetical order:
* AppImage Linux distribution-agnostic binary software deployment
* Flatpak software code is owned and maintained by the not for profit
Flatpak Team, with an open source LGPL-2.1-or-later license.
* Homebrew software code is owned and maintained by its original
author Max Howell, with an open source BSD 2-Clause License.
* Snap software code is owned and maintained by the for profit
Canonical Group Limited, with an open source GNU General Public
License, version 3.0.
Branches
======================================================================
Three branches 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. The current version of 'Stable' is codenamed
'bookworm'.
* '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. The current version of
'Testing' is codenamed 'trixie'.
* '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 two years through the
Long Term Support project. Eventually, 'oldstable' is moved to a
repository for archived releases. Debian 11 is the current Oldstable
release (since 2023-06-10).
* '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 10 is the current
Oldoldstable release (since 2023-06-10).
* '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 11.7, 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.
Branding
======================================================================
Debian has two logos. The [
https://www.debian.org/logos/#open-use
official logo] (also known as o'pen use logo') contains the well-known
Debian 'swirl' and best represents the visual identity of the Debian
Project. A separate, [
https://www.debian.org/logos/#restricted-use
restricted-use logo], also exists for use by the Debian Project and
its members only.
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, and a set
of Debian 2.1 install CDs for the architecture of their choice.
Initially, the swirl was magic smoke arising from an also included
bottle of an Arabian-style genie presented in black profile, but
shortly after was reduced to the red smoke swirl for situations where
space or multiple colours were not an option, and before long the
bottle version effectively was superseded. 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 (
[
https://www.debian.org/logos/officiallogo-100.jpg or the genie] )
that made computers work.
One theory about the origin of the Debian logo is that Buzz Lightyear,
the chosen character for the first named Debian release, has a swirl
in his chin. Stefano Zacchiroli 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 Bruce Perens used to work for Pixar and is
credited as a studio tools engineer on 'Toy Story 2' (1999).
Hardware
======================================================================
Hardware requirements are at least those of the kernel and the GNU
toolsets. Debian's recommended system requirements depend on the level
of installation, which corresponds to increased numbers of installed
components:
Type Minimum RAM size Recommended RAM size Minimum processor clock
speed (IA-32) Hard-drive capacity
Non-desktop 256 MB 512 MB 2 GB
Desktop 1 GB 2 GB 1 GHz 10 GB
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. The installer for z/Architecture 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 interfaces on older or low-end
systems, but the installation of window managers instead of desktop
environments 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: x86-64 architecture with 64-bit userland and supporting
32-bit software
* arm64: ARMv8-A architecture
* armel: Little-endian ARM architecture (ARMv4T instruction set) on
various embedded systems (embedded application binary interface
(EABI)), although support has ended after Buster
* armhf: ARM hard-float architecture (ARMv7 instruction set) requiring
hardware with a floating-point unit
* i386: IA-32 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 architecture supporting POWER7+ and
POWER8 CPUs
* riscv64: 64-bit RISC-V
* s390x: z/Architecture with 64-bit userland, intended to replace s390
Unofficial ports are available as part of the 'unstable' distribution:
* alpha: DEC Alpha architecture
* hppa: HP PA-RISC architecture
* hurd-i386: GNU Hurd kernel on IA-32 architecture
* ia64: Intel Itanium
* loong64: LoongArch
* m68k: Motorola 68k architecture on Amiga, Atari, Macintosh and
various embedded VME systems
* powerpc: 32-bit PowerPC
* ppc64: PowerPC64 architecture supporting 64-bit PowerPC CPUs with
VMX
* sh4: Hitachi SuperH architecture
* sparc64: Sun SPARC architecture with 64-bit userland
* x32: x32 ABI userland for x86-64
Debian supports a variety of ARM-based NAS devices. The NSLU2 was
supported by the installer in Debian 4.0 and 5.0, and Martin Michlmayr
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 (SoC) are supported
too, such as the SheevaPlug 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 points. 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, a low-power open-source hardware 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 'Debian Social Contract' defines a set of basic principles by
which the project and its developers conduct affairs.
* The 'Debian Free Software Guidelines' 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. 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. 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 lists 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 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 Software in the Public Interest,
the owner of the Debian trademark, manager of the monetary donations
and umbrella organization 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 (Cloneproof Schwartz Sequential
Dropping).
Project leadership is distributed occasionally. Branden Robinson was
helped by the Project Scud, 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
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
======================================================================
upstream
↓ align="left" colspan="2" | packaging
package
↓ align="left" colspan="2" | upload
incoming
↓ align="left" colspan="2" | checks
unstable
↓ align="left" colspan="2" | migration
testing
↓ align="left" colspan="2" | freeze
frozen
↓ align="left" colspan="2" | release
stable
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 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 signatures. 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 worldwide. The upload
must be signed using OpenPGP-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.
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. Debian
security advisories are compatible with the Common Vulnerabilities and
Exposures 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 (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. AppArmor 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 and buffer overflow protection,
unlike operating systems such as OpenBSD, but tries to build as many
packages as possible with hardening flags.
In May 2008, a Debian developer discovered that the OpenSSL package
distributed with Debian and derivatives such as Ubuntu made a variety
of security keys vulnerable to a random number generator attack, 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 model. , Black Duck Open Hub
estimated that the current codebase (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 and derivatives have been built upon Debian
over the years. Among the more notable are Ubuntu, developed by
Canonical Ltd. 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, which gained attention in 2014 when it
forked in disagreement over Debian's adoption of the systemd software
suite, and has been mirroring Debian releases since 2017. The Linux
Mint Debian Edition ('LMDE') uses Debian Stable as the software source
base since 2014.
Derivatives and flavors
=========================
Debian is one of the most popular Linux distributions, and many other
distributions have been created from the Debian codebase. ,
DistroWatch 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 Blends 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 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.
Debian GNU/Hurd
=================
Debian GNU/Hurd is a flavor based on the Hurd kernel (which, in turn,
runs on the GNU Mach microkernel), instead of the Linux kernel. 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 (Live CD, Live USB). The
CD uses the IA-32 architecture, making it compatible with IA-32 and
x86-64 PCs. The current version of Debian GNU/Hurd is 2023, published
in June 2023.
Debian GNU/kFreeBSD
=====================
Debian GNU/kFreeBSD is a discontinued Debian flavor. It used the
FreeBSD kernel and GNU userland. The majority of software in Debian
GNU/kFreeBSD was built from the same sources as Debian, with some
kernel packages from FreeBSD. 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, 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,
NDIS, and ZFS as reasons for being interested in the FreeBSD kernel.
It has not been updated since Debian 8. From July 2019, the operating
system continues to be maintained unofficially.As of July 2023, the
development of Debian GNU/kFreeBSD has officially terminated due to
the lack of interest and developers.
See also
======================================================================
* Armbian
* CalyxOS
* Comparison of Linux distributions
* Comparison of mobile operating systems
* Debian version history
* List of Debian project leaders
* List of open source mobile phones
* Pop! OS
* PureOS
* Ubuntu Touch
* Mobian
External links
======================================================================
*
*
[
https://www.techiwiki.info/post/debian-vs-arch-linux-what-is-the-difference-between-the-two-major-types-of-linux-distributions
Debian vs Arch Linux] at [
http://techiwiki.info TechiWiki]
*
* Fosdem 2022,
[
https://archive.fosdem.org/2022/schedule/event/mobile_mobian/ 2 Years
of Mobian Birth and growth of a mobile Linux distribution]
License
=========
All content on Gopherpedia comes from Wikipedia, and is licensed under CC-BY-SA
License URL:
http://creativecommons.org/licenses/by-sa/3.0/
Original Article:
http://en.wikipedia.org/wiki/Debian
