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Comment: Why Not GPL ?
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Comment: TLDP: Default is GFDL 1.2
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##||<tablestyle="width: 100%;" style="border: 0px hidden">~-[:DebianWiki/EditorGuide#translation:Translation(s)]: none-~||<style="text-align: right;border: 0px hidden"> (!) [:/Discussion:Discussion]||
##----
This page is an overview for choosing a new license for wiki.debian.org.

## If your page gets really long, uncomment this Table of Contents
 [[TableOfContents(2)]]
from
== wiki specific constraints ==
 * As opposed to usual documents, wiki pages are usually made of lots of tiny contribution. Therefore the traditional notion of ''author'' probably doesn't apply as usually.
 * Some content should be moved to official material (website, packages, manuals, etc..) once it's mature. Preserving the list of contributors in the new documentation isn't always possible/practical (copyright to 10, 20, or 50 names ?).
 * Wiki have limited space to list copyright holders (when importing/exporting from/to other wikis).
 * Pages are sometimes merged, so we can't have different license for different pages.

== License : Main alternatives ==
We want a license that permit to merge the wiki page in any Debian material (package, website, manual...). There are multiple alternative, but they can be sorted in three families

 A. Keep traditional copyright attribution to page contributors. (i.e apply one or more DFSG license, then list every contributors in the copyright section of the target document).
 A. Do copyright attribution to ''Debian Wiki''. (i.e apply one or more DFSG license. Then, derived work should cite the URL of the original wiki). Creative common's [#cc-by] >= 3.0 is supposed to be particularly well suited for that.
  a. ''variant'' : add a statement that allow anybody to relicense the work under any DFSG compatible license (which make it practical to reuse content anywhere).
 A. Public Domain ''like'' (i.e Allow anybody to reuse the work, without license incompatibility issue). Creative commons' [#CC0] is supposed to be well suited for that. But it doesn't address the problem of imported documents.

== License : Desired features ==

''This table summarize the desired features for the new license.''

|| ||<-5:> License ||
|| ||[#PD] ||[#CC0]||[#BSD]||[#MIT]||[#GFDL]||
||[#Redistribution] || (./) || (./) || (./) || (./) || (./) ||
||[#Allow_Modification] || (./) || (./) || (./) || (./) || (./) ||
||[#Allow Derivative] || (./) || (./) || (./) || (./) || (./) ||
||[#Allow commercial] || (./) || (./) || (./) || (./) || (./) ||
||Attribution || n.a || n.a || Y || :-) || :-( ||
||[#Share_Alike] || n.a || n.a || (./) || (./) || (./) ||

[[Anchor(Redistribution)]]
 Redistribution : :: Allow to redistribute the content in various forms (raw, html, pdf, encrypted...) and on various media (packages, cd). This feature is '''Required'''.

[[Anchor(Allow_Modification)]]
 Allow Modification : :: Allow modification by others (add and remove). This feature is '''Required'''.

[[Anchor(Allow_Derivative)]]
 Allow derivative works : :: Allow Debian derivative distribution to use the document. Allow to reuse content in package Documentation, etc. This feature is '''Required'''.

[[Anchor(Allow_Commercial)]]
 Allow commercial use : :: Allow commercial Debian derivative to reuse the material. This feature is '''Required'''.
 * Debian has commercial derivatives. we want those distribution to be allowed to use our documentation.

[[Anchor(Attribution)]]
 Attribution / Give credits : :: Not required, and actually '''_not_ wanted'''.
 * Even thought we actually want to give credits / attribute a work to it's original author, I believe it isn't possible to __guarantee__ that all work attribution will be preserved over time. Furthermore, the actual name of the author isn't always known). Finally the number of contributors for a given page can make it .

[[Anchor(Share_Alike)]]
 Share Alike : :: Preserve the license on copies. This feature is '''wanted'''.
 * However this doesn't apply except for [#PD PD] where it doesn't apply.
## "can be relicensed in any license which allow free redistribution and modification".

## Mix / Merge with other documents : :: (with same or compatible license) : '''Yes'''.


== Proposed licenses ==
Here are some proposed licenses for the wiki.

[[Anchor(GFDL)]]
=== GFDL 1.2 ===
[http://www.fsf.org/licensing/licenses/fdl.html GFDL] 1.2 License ([wiki:Self:DFSGLicenses#gfdl Debian DFSG], [wiki:WikiPedia:GNU_Free_Documentation_License Wikipedia])

 Attribution : :: The GFDL really focus on attribution, which is a feature we don't want that much.

 * http://wikitravel.org/en/Wikitravel_talk:Why_Wikitravel_isn%27t_GFDL

[[Anchor(MIT)]]
=== MIT ===
[http://www.opensource.org/licenses/mit-license.php MIT] License ([wiki:Self:DFSGLicenses#mit-license Debian DFSG], [wiki:WikiPedia:MIT_License Wikipedia])
 Attribution enforced : :: ''Copyright (c) <year> <copyright holders> [..] The above copyright notice and this permission notice shall be included in all copies'' However it also says ''or substantial portions of the Software''.

[[Anchor(BSD)]]
=== BSD ===
[http://www.opensource.org/licenses/bsd-license.php BSD] License ([http://www.freebsd.org/copyright/freebsd-doc-license.html FreeBSD] copy, [wiki:Self:DFSGLicenses##3clause-bsd Debian DFSG], [wiki:WikiPedia:BSD_licenses Wikipedia]).
 Attribution enforced : :: ''Copyright (c) <YEAR>, <OWNER> ; All rights reserved. [..] Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.''

[[Anchor(public-domain)]] [[Anchor(PD)]]
=== Public Domain ===
Public domain interpretation : [http://creativecommons.org/licenses/publicdomain/ Creative Commons], [wiki:WikiPedia:Public_domain Wikipedia].

 Implicit public domain don't allow duplication : :: [..] The distribution of many types of Internet postings (particularly Usenet articles and messages sent to electronic mailing lists) inherently involves duplication. The act of posting such a work can therefore be taken to imply consent to a certain amount of copying, as dictated by the technical details of the manner of distribution. However, __it does not imply total waiver of copyright__.([http://en.wikipedia.org/wiki/Public_domain#.28Almost.29_everything_written_down_is_copyrighted wikipedia]).

[[Anchor(CC0)]]
=== CC0 Waiver ===
Creative Common's [http://staging.creativecommons.org/licenses/zero/1.0/ CC0 Waiver] ~-([http://wiki.creativecommons.org/CCZero wiki]; [http://creativecommons.org/press-releases/entry/7919 Press-release])-~ is a protocol that enables people to either assert that a work has no legal restrictions attached to it or waive any rights associated with a work so it has no legal restrictions attached to it ~-(quote )-~.

Notes :
 * Basically, CC0 is meant to be a world-wide Public Domain.
 * CC0 is currently (2008-08) a draft, but rumors says that it should be released by the end of the year.

[[Anchor(gpl)]]
=== GPL ===

 * GPL requires to distribute the source with the compiled version. Someone distributing a printed derived work would have to provide the moinmoin wiki code alongside.... Not convenient.
 * A copy of the GPL must be attached to the work... Imagine a 2 page leaflet (like the ''Debian release notes''), with about 8 pages for the GPL license !
 * Is it legal to sell a GPL'ed book ? (for more than the cost of ''physical act of transferring a copy'')


[[Anchor(allow-relicense-license)]]
=== Home made "allow relicense" license ===
Create a home made license which allows to reuse the contents in a another work without giving explicit credits to original authors, if it's under any DFSG compatible license.

 * Pros : Probably what wiki.d.o contributors want.
 * Cons : Yet another ugly home made license.

## Implementation: http://wiki.creativecommons.org/CC0_Implementations
=== See also: ===
 * Licenses For Documentation [[BR]]~-. [http://www.fsf.org/licensing/licenses/index_html#DocumentationLicenses]-~
 * OSI Licenses~-[[BR]]. [http://www.opensource.org/licenses/category]-~
 * Wikipedia : WikiPedia:Free_software_licence
 * http://wikiangela.com/wiki/GNU_Wiki_License Wiki specific licenses.
 * Licenses For Documentation ~-[[BR]]. [http://java.net/choose_license.csp]-~
 * http://wikispot.org/Choosing_a_License

== Sample wiki licenses ==
 * [http://wiki.creativecommons.org/Documentation#license wiki.creativecommons.org] is under [http://creativecommons.org/licenses/by/3.0/ Creative Commons Attribution 3.0 License]
 * [http://gplv3.fsf.org/wiki/index.php/Main_Page#footer fsf.org wiki] is under [http://www.gnu.org/copyleft/fdl.html GFDL]

== Question for Debian-legal ==
 * Does [#PD] and [#CC0] actually allows to reuse some content in a work in a different License (In order to implement that work in any existing documentation).
 * Is [#allow-relicense] a legal concept ?
 * Does images, icons, diagrams and snapshots requires specific statements ?

== Implementation ideas ==
 * Relicensed wikis:
  * Wikipedia wants to switch from [#GFDL] to [#CC-BY-SA].[[BR]]~-. [http://wikimediafoundation.org/wiki/Resolution:License_update]-~
 * Taging:
  * Icon - http://en.wikipedia.org/wiki/Wikipedia:Image_copyright_tags
  * RDFa - http://wiki.creativecommons.org/RDFa
  * XMP - http://partners.adobe.com/public/developer/en/xmp/sdk/XMPspecification.pdf
 * The front page should state the default license.
 * The "Save Changes" screen should display the license.
 * The [:DebianWiki/EditorGuide:EditorGuide] :
  * Should link to "default license page".
  * Should state that specific license are only accepted in specific, exceptional and justified cases. Otherwise, the content will removed from the wiki.
 * ''Except where otherwise noted, content on this site is licensed under a XXX License'' (see CC website)
{{{#!wiki warning
'''This is currently a draft.'''

Amendments to this proposal should be sent by mail to [[http://lists.debian.org/debian-www|debian-www]] mailing list. See [[http://lists.debian.org/debian-www/2009/06/msg00083.html|this thread]].

}}}


''Here's the announcement draft: ''

{{{#!plain
FROM: Debian Wiki Team
TO: Debian-Devel Announce, Debian Project News
SUBJECT: DebianWiki new license
-------------------------------------------------------------------------

Hello,

Currently, wiki.debian.org doesn't have a license. This is an issue as
it prevents re-using and publishing the content anywhere else.

,---[ Executive Summary ]---
|
| This is a proposal to switch the Debian Wiki license to Creative
| Common's BY-SA[1], because that license is DFSG free, it is copyleft
| and it is used on some major wikis.
|
`--------------------------------------------


Our plan goes like this:
1. Build a tool[2] to analyse wiki contributions [DONE]
2. Write a proposal [DONE]
3. Request for review on debian-www [CURRENT]
4. Forward question and RFR debian-legal [TODO]
5. Request for comment (wiki, d-d-a, project-news) [TODO]
6. Submit a poll (doodle.com) [TODO]
7. License the content[4] [TODO]
7a.New license for new contributions & contributors [TODO]
7b.People license their previous contributions[5] [TODO]
7c.Show progress meter icon for each page [TODO]
8. Drop/move non-free pages after a while [TODO]

Wiki constraints
================

We need to choose a license. Obviously that license should be DFSG & OSI
compliant, but we also have some other constraints which are strictly wiki specific:

Lots of contributions:

   A single wiki page can be written by hundreds of contributors.

   Attributing credits to the full list of contributors isn't always
   practical/possible (printed media, video, screen-cast...).


Re-factoring, merging and splitting pages.

   An important task in wiki maintenance is to refactor, rewrite, merge
   and split pages.

   This maintenance makes it difficult to attribute the work. (If one
   moves a paragraph from one page to another, wiki engine doesn't and
   can't reliably track the credits for that paragraph. Only the
   comments/changelog can be used to track it, e.g "Import foo from
   page bar").

   The most efficient way to give credits, it's simply to link to
   the page history.


Re-using wiki content.

   It should be possible and easy to re-use the content of a wiki page
   in various situation: software documentation, Debian manuals,
   release notes, printed papers, etc.

   Re-distributing the "source code" of wiki pages (i.e wiki markup)
   isn't practical, especially for printed media.


Inter wiki collaboration.

   Sharing and synchronizing wiki pages among wikis (Debian derivatives,
   Upstream, Wikipedia, tldp.org ...)

   So far, wikis have proven to be effective for collaboration _inside_
   a project, but there has been no collaboration among wikis.
   There are probably two major reasons for that: incompatible licenses
   and the lack of tools.
   Wikis should use the same license, so it is possible to re-use,
   share, import and export content among wikis.
   Also, we need some Distributed VCS ^W Wiki-engine with conditional
   paragraph and variable substitution, à la WML (Website Meta
   Language)[3], but that's another story.


Homepages

   The wiki contains some homepages, which may contain private data
   (email address, telephone number or personal opinions)

   Homepages are not meant to be redistributed. Those data may need
   a special statement or a different copyright/license.
   Admins should be allowed to modify and delete homepages.


Dual license
------------

   The wiki, at large, must have only one single default license: If
   the wiki were dual licensed, it would be almost impossible to
   import any content, excepted if that content were already under
   the same two licenses.

   However, we recognize that some content can't be re-licensed under
   the new license (because we can't get previous contributors to
   re-license their contributions, or because the content is *meant* to
   be re-used in a document under $GIVEN license,).
   Only DFSG-free licenses are allowed.

   Therefore, we plan to allow the following two exceptions:
     "This page is dual licensed under $WIKILICENSE and $OTHERLICENSE".
   and
     "This page is licensed under $OTHERLICENSE. New contributions
      since $DATE are also licensed under $WIKILICENSE".


Copyleft?
---------
   One important argument in the debate about liberal licenses (BSD,
   CCZero) versus copyleft licenses (GPL, CC-BY-SA) it's that we want
   to be able to collaborate (branch) wiki pages with Debian upstream,
   Debian derivatives and other documentation initiatives.

   It is important for open-source movement to be able to collaborate
   on documentation. This collaboration _must_not_exclude_commercial_
   actors of the free software movement. Those companies, even more
   than individual contributors, wouldn't let a competitor re-use their
   work in non-free material. Therefore copyleft licenses are likely
   to get more contributions from companies.

   Note:
     Companies publishing documentations, seems to follow one of the
     two following strategies:
     - Use a license that strongly give credits to them, like OPL,
       GFDL with cover-page, or CC-BY-ND.
     - Use a license that guarantees that the work will remain free
       (GFDL with no cover-page, or CC-BY-SA)
     None of them seems to use liberal license.


Constraints summary
-------------------
1. The license must be DFSG and OSI compliant.
2. The license should allow attribution through URL and changelog.
3. The license should not impose redistribution of the source code.
4. The license should be widely used for wikis and/or documentation.

Choosing a license
==================

Public Domain
  Pros:
   - The content can be re-used anywhere.
   - No need to list authors
  Cons:
   - In many countries, one can't put material under public domain.
   - Don't allow importing existing material (Almost no existing
     content is published as PD).
  => REJECTED: Not international.

CC-Zero
  Pros:
   - An international implementation of something like public domain.
  Cons:
   - Seems to need an explicit waiving procedure.
     (See CC's tool: http://creativecommons.org/license/zero/ )
   - Don't allow importing material from other wikis(except content
     under Public-domain or CCzero).
  => REJECTED: Not wide-spread, no content can be imported at this time.

BSD, MIT, LGPL...
  Pros:
   - Liberal license
   - Don't prevent re-using the content in a book or paying support.
  Cons:
   - Liberal license
   - Don't prevent re-using the content in a boot or paying support.
  => REJECTED: Not wide-spread for documentation. Don't protect
               contributing companies "investment" (no guarantee to
               remain free).

OPL
  REJECTED: Doesn't comply with DFSG ( http://bugs.debian.org/238245 )

GPL
  Pros:
   - Copyleft
   - Content re-usable in GPL documentation
   - Used by many documentation (but we don't need to import them).
  Cons:
   - Requires to distribute "source code" alongside "compiled".
     (i.e provide wiki markup code alongside printed leaflet?!)
   - Provide a full copy of the license. (even with a leaflet!)
  => REJECTED: - redistribution of source isn't desired.
               - embedding the license isn't always practical.

CC-BY-SA
  Pros:
   - Copyleft
   - Content re-usable in GPL documentation
   - Used by Wikipedia and Ubuntu
   - Compatible with GPL2 (which is used by some existing Debian docs)
  Cons:
   - Currently this license isn't used in Debian documentations.
  => ACCEPTED.

Proposal
========

Based on the fact above, the license CC-BY-SA (3.0) seems to be the most
suitable license as it meets all the criteria.
As a reminder, the two most important criteria are 1. Choose a "free" license 2. Choose a license that is already widely used.



************
*** TODO ***
************

Questions for debian-legal
- Are small contributions similar to "fair use"?
- Assuming a wiki page is made of lots of small contribution. Can we
  consider that copying the page (all the small contribution) is a
  fair use of each contribution?
- Does images, icons, diagrams and snapshots requires specific
  statements?


Wiki licensing statement
-------------------
* Add some statements about copyright attribution
  ... The Copyright attribution is done by linking to page's URL
  (which has a link to the revision history, with the list of
  contributions)...
   
* Add some statements about homepages content:
  Hint, Apache license has:
> 6. Trademarks. This License does not grant permission to use the trade
> names, trademarks, service marks, or product names of the Licensor,
> except as required for reasonable and customary use in describing
> the origin of the Work and reproducing the content of the NOTICE
> file.

* Add some statement about content administration?
  This is probably not needed as it's implied in a wiki
> 3. you acknowledge and agree that the site editor will have the
> right (but not obligation), at the site editor's entire
> discretion, to refuse to publish, or to remove, or to block
> access to any content you provide, at any time and for any
> reason, with or without notice.


Misc Information
================

Some documentation in other projects, and their licenses
--------------------------------------------------------

 Ubuntu: CC-BY-SA (>=2.5)
  https://wiki.ubuntu.com/DocumentationTeam/License
 Wikipedia: CC-BY-SA (>=3.0)
  http://meta.wikimedia.org/wiki/Licensing_update
 Opensuse: GFDL
  http://en.opensuse.org/Legal
 Fedora: CC-BY-SA (>=3.0)
  http://fedoraproject.org/wiki/Legal/Licenses
 Gentoo: CC-BY-NC-SA (>=3.0)
  http://en.gentoo-wiki.com/wiki/Creative_Commons
 TLDP: An aggregate of HowTos with various licenses. Default is GFDL 1.2
  http://wiki.tldp.org/LdpWikiDefaultLicence


Some statistics about Debian wiki:
----------------------------------

  The wiki has about 6500 pages (plus 2500 deleted or merged pages).
  About 3500 contributors have made about 84000 editions.
  The top 10 contributors have contributed 23% of the words*
  The top 70 contributors have contributed 50% of the words*
  The top 440 contributors have contributed 80% of the words*
  The top 2000 contributors have contributed 90% of the words*
  The remaining contributors have contributed less than 25 words* each.
 *) In these statistics, words are counted in a special way (version
    numbers and code-names are ignored, links are ignored, etc.)


[[TODO: SIGN HERE]]

----
[1] http://creativecommons.org/licenses/by-sa/
[2] http://www.klabs.be/wiki-stats/
[3] http://packages.debian.org/stable/wml
[4] http://wiki.debian.org/DebianWiki/LicencingTerms/RelicensingStrategy
[5] http://wiki.debian.org/DebianWiki/LicenseAllMyContributionGroup
}}}

This is currently a draft.

Amendments to this proposal should be sent by mail to debian-www mailing list. See this thread.

Here's the announcement draft:

FROM: Debian Wiki Team
TO: Debian-Devel Announce, Debian Project News
SUBJECT: DebianWiki new license
-------------------------------------------------------------------------

Hello,

Currently, wiki.debian.org doesn't have a license. This is an issue as
it prevents re-using and publishing the content anywhere else.

,---[ Executive Summary ]---
|
|  This is a proposal to switch the Debian Wiki license to Creative
|  Common's BY-SA[1], because that license is DFSG free, it is copyleft
|  and it is used on some major wikis.
|
`--------------------------------------------


Our plan goes like this:
1. Build a tool[2] to analyse wiki contributions     [DONE]
2. Write a proposal                                  [DONE]
3. Request for review on debian-www                  [CURRENT]
4. Forward question and RFR debian-legal             [TODO]
5. Request for comment (wiki, d-d-a, project-news)   [TODO]
6. Submit a poll (doodle.com)                        [TODO]
7. License the content[4]                            [TODO]
7a.New license for new contributions & contributors  [TODO]
7b.People license their previous contributions[5]    [TODO]
7c.Show progress meter icon for each page            [TODO]
8. Drop/move non-free pages after a while            [TODO]

Wiki constraints
================

We need to choose a license. Obviously that license should be DFSG & OSI
compliant, but we also have some other constraints which are strictly wiki specific:

Lots of contributions:

   A single wiki page can be written by hundreds of contributors. 

   Attributing credits to the full list of contributors isn't always
   practical/possible (printed media, video, screen-cast...).


Re-factoring, merging and splitting pages.

   An important task in wiki maintenance is to refactor, rewrite, merge
   and split pages.

   This maintenance makes it difficult to attribute the work. (If one
   moves a paragraph from one page to another, wiki engine doesn't and
   can't reliably track the credits for that paragraph. Only the
   comments/changelog can be used to track it, e.g "Import foo from 
   page bar").

   The most efficient way to give credits, it's simply to link to
   the page history.


Re-using wiki content.

   It should be possible and easy to re-use the content of a wiki page
   in various situation: software documentation, Debian manuals, 
   release notes, printed papers, etc.

   Re-distributing the "source code" of wiki pages (i.e wiki markup)
   isn't practical, especially for printed media.


Inter wiki collaboration.

   Sharing and synchronizing wiki pages among wikis (Debian derivatives,
   Upstream, Wikipedia, tldp.org ...)

   So far, wikis have proven to be effective for collaboration _inside_
   a project, but there has been no collaboration among wikis.
   There are probably two major reasons for that: incompatible licenses
   and the lack of tools.
   Wikis should use the same license, so it is possible to re-use,
   share, import and export content among wikis.
   Also, we need some Distributed VCS ^W Wiki-engine with conditional
   paragraph and variable substitution, à la WML (Website Meta
   Language)[3], but that's another story.


Homepages

   The wiki contains some homepages, which may contain private data
   (email address, telephone number or personal opinions)

   Homepages are not meant to be redistributed. Those data may need
   a special statement or a different copyright/license.
   Admins should be allowed to modify and delete homepages.


Dual license
------------

   The wiki, at large, must have only one single default license: If 
   the wiki were dual licensed, it would be almost impossible to 
   import any content, excepted if that content were already under
   the same two licenses.

   However, we recognize that some content can't be re-licensed under
   the new license (because we can't get previous contributors to
   re-license their contributions, or because the content is *meant* to
   be re-used  in a document under $GIVEN license,).
   Only DFSG-free licenses are allowed.

   Therefore, we plan to allow the following two exceptions:
     "This page is dual licensed under $WIKILICENSE and $OTHERLICENSE".
   and
     "This page is licensed under $OTHERLICENSE. New contributions
      since $DATE are also licensed under $WIKILICENSE".


Copyleft?
---------
   One important argument in the debate about liberal licenses (BSD,
   CCZero) versus copyleft licenses (GPL, CC-BY-SA) it's that we want
   to be able to collaborate (branch) wiki pages with Debian upstream,
   Debian derivatives and other documentation initiatives.

   It is important for open-source movement to be able to collaborate
   on documentation. This collaboration _must_not_exclude_commercial_
   actors of the free software movement. Those companies, even more 
   than individual contributors, wouldn't let a competitor re-use their
   work in non-free material. Therefore copyleft licenses are likely
   to get more contributions from companies.

   Note:
     Companies publishing documentations, seems to follow one of the
     two following strategies:
     - Use a license that strongly give credits to them, like OPL, 
       GFDL with cover-page, or CC-BY-ND.
     - Use a license that guarantees that the work will remain free
       (GFDL with no cover-page, or CC-BY-SA)
     None of them seems to use liberal license.


Constraints summary
-------------------
1. The license must be DFSG and OSI compliant.
2. The license should allow attribution through URL and changelog.
3. The license should not impose redistribution of the source code.
4. The license should be widely used for wikis and/or documentation.

Choosing a license
==================

Public Domain
  Pros:
   - The content can be re-used anywhere.
   - No need to list authors
  Cons:
   - In many countries, one can't put material under public domain.
   - Don't allow importing existing material (Almost no existing
     content is published as PD).
  => REJECTED: Not international.

CC-Zero
  Pros:
   - An international implementation of something like public domain.
  Cons:
   - Seems to need an explicit waiving procedure.
     (See CC's tool: http://creativecommons.org/license/zero/ )
   - Don't allow importing material from other wikis(except content
     under Public-domain or CCzero).
  => REJECTED: Not wide-spread, no content can be imported at this time.

BSD, MIT, LGPL...
  Pros:
   - Liberal license
   - Don't prevent re-using the content in a book or paying support.
  Cons:
   - Liberal license
   - Don't prevent re-using the content in a boot or paying support.
  => REJECTED: Not wide-spread for documentation. Don't protect
               contributing companies "investment" (no guarantee to
               remain free).

OPL
  REJECTED: Doesn't comply with DFSG ( http://bugs.debian.org/238245 )

GPL
  Pros:
   - Copyleft
   - Content re-usable in GPL documentation
   - Used by many documentation (but we don't need to import them).
  Cons:
   - Requires to distribute "source code" alongside "compiled".
     (i.e provide wiki markup code alongside printed leaflet?!)
   - Provide a full copy of the license. (even with a leaflet!)
  => REJECTED: - redistribution of source isn't desired.
               - embedding the license isn't always practical.

CC-BY-SA
  Pros:
   - Copyleft
   - Content re-usable in GPL documentation
   - Used by Wikipedia and Ubuntu
   - Compatible with GPL2 (which is used by some existing Debian docs)
  Cons:
   - Currently this license isn't used in Debian documentations.
  => ACCEPTED.

Proposal
========

Based on the fact above, the license CC-BY-SA (3.0) seems to be the most
suitable license as it meets all the criteria.
As a reminder, the two most important criteria are  1. Choose a "free" license  2. Choose a license that is already widely used.



************
*** TODO ***
************

Questions for debian-legal
- Are small contributions similar to "fair use"?
- Assuming a wiki page is made of lots of small contribution. Can we
  consider that copying the page (all the small contribution) is a 
  fair use of each contribution?
- Does images, icons, diagrams and snapshots requires specific
  statements?


Wiki licensing statement
-------------------
* Add some statements about copyright attribution
  ... The Copyright attribution is done by linking to page's URL
  (which has a link to the revision history, with the list of
  contributions)...
   
* Add some statements about homepages content:
  Hint, Apache license has:
> 6. Trademarks. This License does not grant permission to use the trade
>    names, trademarks, service marks, or product names of the Licensor,
>    except as required for reasonable and customary use in describing
>    the origin of the Work and reproducing the content of the NOTICE
>    file.

* Add some statement about content administration?
  This is probably not needed as it's implied in a wiki
>      3. you acknowledge and agree that the site editor will have the
>         right (but not obligation), at the site editor's entire
>         discretion, to refuse to publish, or to remove, or to block
>         access to any content you provide, at any time and for any
>         reason, with or without notice.


Misc Information
================

Some documentation in other projects, and their licenses
--------------------------------------------------------

 Ubuntu: CC-BY-SA (>=2.5)
  https://wiki.ubuntu.com/DocumentationTeam/License
 Wikipedia: CC-BY-SA (>=3.0)
  http://meta.wikimedia.org/wiki/Licensing_update
 Opensuse: GFDL
  http://en.opensuse.org/Legal
 Fedora: CC-BY-SA (>=3.0)
  http://fedoraproject.org/wiki/Legal/Licenses
 Gentoo: CC-BY-NC-SA (>=3.0)
  http://en.gentoo-wiki.com/wiki/Creative_Commons
 TLDP: An aggregate of HowTos with various licenses. Default is GFDL 1.2
  http://wiki.tldp.org/LdpWikiDefaultLicence


Some statistics about Debian wiki:
----------------------------------

  The wiki has about 6500 pages (plus 2500 deleted or merged pages).
  About 3500 contributors have made about 84000 editions.
  The top 10 contributors have contributed 23% of the words*
  The top 70 contributors have contributed 50% of the words*
  The top 440 contributors have contributed 80% of the words*
  The top 2000 contributors have contributed 90% of the words*
  The remaining contributors have contributed less than 25 words* each.
 *) In these statistics, words are counted in a special way (version
    numbers and code-names are ignored, links are ignored, etc.)


[[TODO: SIGN HERE]]

----
[1] http://creativecommons.org/licenses/by-sa/
[2] http://www.klabs.be/wiki-stats/
[3] http://packages.debian.org/stable/wml
[4] http://wiki.debian.org/DebianWiki/LicencingTerms/RelicensingStrategy
[5] http://wiki.debian.org/DebianWiki/LicenseAllMyContributionGroup