The Debian Archive
==================
The Debian system is maintained and distributed as a collection of
*packages*. Since there are so many of them (currently well over 15000),
they are split into *sections* and given *priorities* to simplify the
handling of them.
The effort of the Debian project is to build a free operating system,
but not every package we want to make accessible is *free* in our sense
(see the Debian Free Software Guidelines, below), or may be
imported/exported without restrictions. Thus, the archive is split into
areas [1]_ based on their licenses and other restrictions.
The aims of this are:
- to allow us to make as much software available as we can
- to allow us to encourage everyone to write free software, and
- to allow us to make it easy for people to produce CD-ROMs of our
system without violating any licenses, import/export restrictions, or
any other laws.
The *main* archive area forms the *Debian distribution*.
Packages in the other archive areas (``non-free-firmware``,
``contrib``, ``non-free``) are not considered to be part of the Debian
distribution, although we support their use and provide infrastructure
for them (such as our bug-tracking system and mailing lists). This
Debian Policy Manual applies to these packages as well.
.. [1]
The Debian archive software uses the term "component" internally and
in the Release file format to refer to the division of an archive.
The Debian Social Contract simply refers to "areas." This document
uses terminology similar to the Social Contract.
.. _s-dfsg:
The Debian Free Software Guidelines
-----------------------------------
The Debian Free Software Guidelines (DFSG) form our definition of "free
software". These are:
1. Free Redistribution
The license of a Debian component may not restrict any party from
selling or giving away the software as a component of an aggregate
software distribution containing programs from several different
sources. The license may not require a royalty or other fee for such
sale.
2. Source Code
The program must include source code, and must allow distribution in
source code as well as compiled form.
3. Derived Works
The license must allow modifications and derived works, and must
allow them to be distributed under the same terms as the license of
the original software.
4. Integrity of The Author's Source Code
The license may restrict source-code from being distributed in
modified form *only* if the license allows the distribution of
"patch files" with the source code for the purpose of modifying the
program at build time. The license must explicitly permit
distribution of software built from modified source code. The
license may require derived works to carry a different name or
version number from the original software. (This is a compromise.
The Debian Project encourages all authors to not restrict any files,
source or binary, from being modified.)
5. No Discrimination Against Persons or Groups
The license must not discriminate against any person or group of
persons.
6. No Discrimination Against Fields of Endeavor
The license must not restrict anyone from making use of the program
in a specific field of endeavor. For example, it may not restrict
the program from being used in a business, or from being used for
genetic research.
7. Distribution of License
The rights attached to the program must apply to all to whom the
program is redistributed without the need for execution of an
additional license by those parties.
8. License Must Not Be Specific to Debian
The rights attached to the program must not depend on the program's
being part of a Debian system. If the program is extracted from
Debian and used or distributed without Debian but otherwise within
the terms of the program's license, all parties to whom the program
is redistributed must have the same rights as those that are granted
in conjunction with the Debian system.
9. License Must Not Contaminate Other Software
The license must not place restrictions on other software that is
distributed along with the licensed software. For example, the
license must not insist that all other programs distributed on the
same medium must be free software.
10. Example Licenses
The "GPL," "BSD," and "Artistic" licenses are examples of licenses
that we consider *free*.
.. _s-sections:
Archive areas
-------------
.. _s-main:
The main archive area
~~~~~~~~~~~~~~~~~~~~~
The *main* archive area comprises the Debian distribution. Only the
packages in this area are considered part of the distribution. None of
the packages in the *main* archive area require software outside of that
area to function. Anyone may use, share, modify and redistribute the
packages in this archive area freely [2]_.
Every package in *main* must comply with the DFSG (Debian Free Software
Guidelines). [3]_
In addition, the packages in *main*
- must not require or recommend a package outside of *main* for
compilation or execution (thus, the package must not declare a
``Pre-Depends``, ``Depends``, ``Recommends``, ``Build-Depends``,
``Build-Depends-Indep``, or ``Build-Depends-Arch`` relationship on a
non-*main* package unless that package is only listed as a non-default
alternative for a package in *main*),
- must not be so buggy that we refuse to support them, and
- must meet all policy requirements presented in this manual.
If a source package is in the *main* archive area, then at least one of
its binary packages must be in the *main* archive area, and each of the
remaining packages must be in either the *main* or *contrib* archive
area. Each binary package's archive area is indicated by its ``Section``
field: see :ref:`s-subsections`.
Source packages in *main* with a mixture of *main* and *contrib* binary
packages are more complex for archive tooling to handle, and therefore
should be limited to situations where it would be inconvenient to split
the source package. If it is straightforward to split the source package
into a *main* part and a *contrib* part that are built separately, then
those parts should be represented as separate source packages.
When a *main* source package has a mixture of *main* and *contrib* binary
packages, the source package and the *main* binary packages must follow
the requirements for *main* packages, but the *contrib* binary packages
may follow the weaker requirements for *contrib* packages. In particular,
source packages in *main* must not have build dependencies outside *main*,
but the *contrib* binary packages may have runtime dependencies outside
*main*.
.. [2]
See `What Does Free Mean? <https://www.debian.org/intro/free>`_ for
more about what we mean by free software.
.. [3]
Debian's FTP Masters publish a
`REJECT-FAQ <https://ftp-master.debian.org/REJECT-FAQ.html>`_ which
details the project's current working interpretation of the DFSG.
.. _s-non-free-firmware:
The non-free-firmware archive area
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The *non-free-firmware* archive area contains packages providing
firmware needed to initialize, use or keep updated hardware required
by our users, typically necessary for important functions to be
available (i.e. wireless network connectivity) or for fixing security
defects in hardware (i.e. CPU microcode updates). Packages in this
archive may not comply with all of the policy requirements in this
manual due to lack of source code availability, restrictions on
modification or other limitations.
Packages in *non-free-firmware*
- must not be so buggy that we refuse to support them, and
- must meet all policy requirements presented in this manual that it is
possible for them to meet. [4]_
.. _s-contrib:
The contrib archive area
~~~~~~~~~~~~~~~~~~~~~~~~
The *contrib* archive area contains supplemental packages intended to
work with the Debian distribution, but which require software outside of
the distribution to either build or function.
Every package in *contrib* must comply with the DFSG.
In addition, the packages in *contrib*
- must not be so buggy that we refuse to support them, and
- must meet all policy requirements presented in this manual.
Examples of packages which would be included in *contrib* are:
- free packages which require *contrib*, *non-free* packages or
packages which are not in our archive at all for compilation or
execution, and
- wrapper packages or other sorts of free accessories for non-free
programs.
If a source package is in the *contrib* archive area, then each of the
binary packages that it produces must also be in the *contrib* archive
area.
.. _s-non-free:
The non-free archive area
~~~~~~~~~~~~~~~~~~~~~~~~~
The *non-free* archive area contains supplemental packages intended to
work with the Debian distribution that do not comply with the DFSG or
have other problems that make their distribution problematic. They may
not comply with all of the policy requirements in this manual due to
restrictions on modifications or other limitations.
Packages must be placed in *non-free* if they are not compliant with the
DFSG or are encumbered by patents or other legal issues that make their
distribution problematic.
In addition, the packages in *non-free*
- must not be so buggy that we refuse to support them, and
- must meet all policy requirements presented in this manual that it is
possible for them to meet. [4]_
If a source package is in the *non-free* archive area, then each of the
binary packages that it produces must also be in the *non-free* archive
area.
.. [4]
It is possible that there are policy requirements which the package
is unable to meet, for example, if the source is unavailable. These
situations will need to be handled on a case-by-case basis.
.. _s-pkgcopyright:
Copyright considerations
------------------------
Every package must be accompanied by a verbatim copy of its
distribution license(s) in the file ``/usr/share/doc/PACKAGE/copyright``.
The copyright information for files in a package must be copied
verbatim into ``/usr/share/doc/PACKAGE/copyright``, when all of the
following hold:
#. the distribution license for those files requires that copyright
information be included in all copies and/or binary distributions;
#. the files are shipped in the binary package, either in source or
compiled form; and
#. the form in which the files are present in the binary package does
not include a plain text version of their copyright notices.
Thus, the copyright information for files in the source package which
are only part of its build process, such as autotools files, need not
be included in ``/usr/share/doc/PACKAGE/copyright``, because those
files do not get installed into the binary package. Similarly, plain
text files which include their own copyright information and are
installed into the binary package unmodified need not have that
copyright information copied into ``/usr/share/doc/PACKAGE/copyright``
However, the copyright notices for any files which are compiled into
the object code shipped in the binary package must all be included in
``/usr/share/doc/PACKAGE/copyright`` when the license requires that
copyright information be included in all copies and/or binary
distributions, as most do. [5]_
See :ref:`s-copyrightfile` for further details.
We reserve the right to restrict files from being included anywhere in
our archives if
- their use or distribution would break a law,
- there is an ethical conflict in their distribution or use,
- we would have to sign a license for them, or
- their distribution would conflict with other project policies.
Programs whose authors encourage the user to make donations are fine for
the main distribution, provided that the authors do not claim that not
donating is immoral, unethical, illegal or something similar; in such a
case they must go in *non-free*.
Packages whose copyright permission notices (or patent problems) do not
even allow redistribution of binaries only, and where no special
permission has been obtained, must not be placed on the Debian FTP site
and its mirrors at all.
Note that under international copyright law (this applies in the United
States, too), *no* distribution or modification of a work is allowed
without an explicit notice saying so. Therefore a program without a
copyright notice *is* copyrighted and you may not do anything to it
without risking being sued! Likewise if a program has a copyright notice
but no statement saying what is permitted then nothing is permitted.
Many authors are unaware of the problems that restrictive copyrights (or
lack of copyright notices) can cause for the users of their
supposedly-free software. It is often worthwhile contacting such authors
diplomatically to ask them to modify their license terms. However, this
can be a politically difficult thing to do and you should ask for advice
on the ``debian-legal`` mailing list first, as explained below.
When in doubt about a copyright, send mail to
debian-legal@lists.debian.org. Be prepared to provide us with the
copyright statement. Software covered by the GPL, public domain software
and BSD-like copyrights are safe; be wary of the phrases "commercial use
prohibited" and "distribution restricted".
.. [5]
Licenses that are not thought to require the copying of all
copyright notices into Debian's copyright file include Apache-2.0
and the Boost Software License, version 1.0. Final determination
as to whether a package's copyright file is sufficient lies with
the FTP team.
To help find copyright notices you need to copy, you might try
``grep --color=always -Eir '(copyright|©)' * | less -R``
.. _s-subsections:
Sections
--------
The packages in the archive areas *main*, *non-free-firmware*, *contrib*
and *non-free* are grouped further into *sections* to simplify handling.
The archive area and section for each package should be specified in the
package's ``Section`` control field (see
:ref:`s-f-Section`). However, the maintainer of the
Debian archive may override this selection to ensure the consistency of
the Debian distribution. The ``Section`` field should be of the form:
- *section* if the package is in the *main* archive area,
- *area/section* if the package is in the *non-free-firmware*, *contrib*
or *non-free* archive areas.
The Debian archive maintainers provide the authoritative list of
sections. At present, they are: admin, cli-mono, comm, database, debug,
devel, doc, editors, education, electronics, embedded, fonts, games,
gnome, gnu-r, gnustep, graphics, hamradio, haskell, httpd, interpreters,
introspection, java, javascript, kde, kernel, libdevel, libs, lisp,
localization, mail, math, metapackages, misc, net, news, ocaml, oldlibs,
otherosfs, perl, php, python, ruby, rust, science, shells, sound, tasks,
tex, text, utils, vcs, video, web, x11, xfce, zope. The additional
section *debian-installer* contains special packages used by the
installer and is not used for normal Debian packages.
For more information about the sections and their definitions, see the
`list of sections in
unstable <https://packages.debian.org/unstable/>`_.
.. _s-priorities:
Priorities
----------
Each package must have a *priority* value, which is set in the metadata
for the Debian archive and is also included in the package's control
files (see :ref:`s-f-Priority`). This information is used
to control which packages are included in standard or minimal Debian
installations.
Most Debian packages will have a priority of ``optional``. Priority
levels other than ``optional`` are only used for packages that should be
included by default in a standard installation of Debian.
The priority of a package is determined solely by the functionality it
provides directly to the user. The priority of a package should not be
increased merely because another higher-priority package depends on it;
instead, the tools used to construct Debian installations will correctly
handle package dependencies. In particular, this means that C-like
libraries will almost never have a priority above ``optional``, since
they do not provide functionality directly to users. However, as an
exception, the maintainers of Debian installers may request an increase
of the priority of a package to resolve installation issues and ensure
that the correct set of packages is included in a standard or minimal
install.
The following *priority levels* are recognized by the Debian package
management tools.
``required``
Packages which are necessary for the proper functioning of the
system (usually, this means that dpkg functionality depends on these
packages). Removing a ``required`` package may cause your system to
become totally broken and you may not even be able to use ``dpkg``
to put things back, so only do so if you know what you are doing.
Systems with only the ``required`` packages installed have at least
enough functionality for the sysadmin to boot the system and install
more software.
``important``
Important programs, including those which one would expect to find
on any Unix-like system. If the expectation is that an experienced
Unix person who found it missing would say "What on earth is going
on, where is ``foo``?", it must be an ``important`` package. [6]_
Other packages without which the system will not run well or be
usable must also have priority ``important``. This does *not*
include Emacs, the X Window System, TeX or any other large
applications. The ``important`` packages are just a bare minimum of
commonly-expected and necessary tools.
``standard``
These packages provide a reasonably small but not too limited
character-mode system. This is what will be installed by default if
the user doesn't select anything else. It doesn't include many large
applications.
Two packages that both have a priority of ``standard`` or higher must
not conflict with each other.
``optional``
This is the default priority for the majority of the archive. Unless
a package should be installed by default on standard Debian systems,
it should have a priority of ``optional``. Packages with a priority
of ``optional`` may conflict with each other.
``extra``
*This priority is deprecated.* Use the ``optional`` priority
instead. This priority should be treated as equivalent to
``optional``.
The ``extra`` priority was previously used for packages that
conflicted with other packages and packages that were only likely to
be useful to people with specialized requirements. However, this
distinction was somewhat arbitrary, not consistently followed, and
not useful enough to warrant the maintenance effort.
.. [6]
This is an important criterion because we are trying to produce,
amongst other things, a free Unix.