path: root/user-guide/C/sgml/fdl.sgml

<chapter id="fdl">

  <title>GNU Free Documentation License</title>

  <sect1 id="fdl-preamble">
    <title>0. PREAMBLE</title>
    <para>
      The purpose of this License is to make a manual, textbook, or
      other written document <quote>free</quote> in the sense of
      freedom: to assure everyone the effective freedom to copy and
      redistribute it, with or without modifying it, either
      commercially or noncommercially. Secondarily, this License
      preserves for the author and publisher a way to get credit for
      their work, while not being considered responsible for
      modifications made by others.
    </para>
    
    <para>
      This License is a kind of <quote>copyleft</quote>, which means
      that derivative works of the document must themselves be free in
      the same sense. It complements the GNU General Public License,
      which is a copyleft license designed for free software.
    </para>
    
    <para>
      We have designed this License in order to use it for manuals for
      free software, because free software needs free documentation: a
      free program should come with manuals providing the same
      freedoms that the software does. But this License is not limited
      to software manuals; it can be used for any textual work,
      regardless of subject matter or whether it is published as a
      printed book. We recommend this License principally for works
      whose purpose is instruction or reference.
    </para>
  </sect1>
  <sect1 id="fdl-section1">
    <title>1. APPLICABILITY AND DEFINITIONS</title>
    <para id="fdl-document">
      This License applies to any manual or other work that contains a
      notice placed by the copyright holder saying it can be
      distributed under the terms of this License. The
      <quote>Document</quote>, below, refers to any such manual or
      work. Any member of the public is a licensee, and is addressed
      as <quote>you</quote>.
    </para>
    
    <para id="fdl-modified">
      A <quote>Modified Version</quote> of the Document means any work
      containing the Document or a portion of it, either copied
      verbatim, or with modifications and/or translated into another
      language.
    </para>
	
    <para id="fdl-secondary">
      A <quote>Secondary Section</quote> is a named appendix or a
      front-matter section of the <link
      linkend="fdl-document">Document</link> that deals exclusively
      with the relationship of the publishers or authors of the
      Document to the Document's overall subject (or to related
      matters) and contains nothing that could fall directly within
      that overall subject. (For example, if the Document is in part a
      textbook of mathematics, a Secondary Section may not explain any
      mathematics.)  The relationship could be a matter of historical
      connection with the subject or with related matters, or of
      legal, commercial, philosophical, ethical or political position
      regarding them.
    </para>

    <para id="fdl-invariant">
      The <quote>Invariant Sections</quote> are certain <link
      linkend="fdl-secondary"> Secondary Sections</link> whose titles
      are designated, as being those of Invariant Sections, in the
      notice that says that the <link
      linkend="fdl-document">Document</link> is released under this
      License.
    </para>
    
    <para id="fdl-cover-texts">
      The <quote>Cover Texts</quote> are certain short passages of
      text that are listed, as Front-Cover Texts or Back-Cover Texts,
      in the notice that says that the <link
      linkend="fdl-document">Document</link> is released under this
      License.
    </para>
	
    <para id="fdl-transparent">
      A <quote>Transparent</quote> copy of the <link
      linkend="fdl-document"> Document</link> means a machine-readable
      copy, represented in a format whose specification is available
      to the general public, whose contents can be viewed and edited
      directly and straightforwardly with generic text editors or (for
      images composed of pixels) generic paint programs or (for
      drawings) some widely available drawing editor, and that is
      suitable for input to text formatters or for automatic
      translation to a variety of formats suitable for input to text
      formatters. A copy made in an otherwise Transparent file format
      whose markup has been designed to thwart or discourage
      subsequent modification by readers is not Transparent.  A copy
      that is not <quote>Transparent</quote> is called
      <quote>Opaque</quote>.
    </para>
    
    <para>
      Examples of suitable formats for Transparent copies include
      plain ASCII without markup, Texinfo input format, LaTeX input
      format, SGML or XML using a publicly available DTD, and
      standard-conforming simple HTML designed for human
      modification. Opaque formats include PostScript, PDF,
      proprietary formats that can be read and edited only by
      proprietary word processors, SGML or XML for which the DTD
      and/or processing tools are not generally available, and the
      machine-generated HTML produced by some word processors for
      output purposes only.
    </para>
    
    <para id="fdl-title-page">
      The <quote>Title Page</quote> means, for a printed book, the
      title page itself, plus such following pages as are needed to
      hold, legibly, the material this License requires to appear in
      the title page. For works in formats which do not have any title
      page as such, <quote>Title Page</quote> means the text near the
      most prominent appearance of the work's title, preceding the
      beginning of the body of the text.
    </para>
  </sect1>
    
  <sect1 id="fdl-section2">
    <title>2. VERBATIM COPYING</title>
    <para>
      You may copy and distribute the <link
      linkend="fdl-document">Document</link> in any medium, either
      commercially or noncommercially, provided that this License, the
      copyright notices, and the license notice saying this License
      applies to the Document are reproduced in all copies, and that
      you add no other conditions whatsoever to those of this
      License. You may not use technical measures to obstruct or
      control the reading or further copying of the copies you make or
      distribute. However, you may accept compensation in exchange for
      copies. If you distribute a large enough number of copies you
      must also follow the conditions in <link
      linkend="fdl-section3">section 3</link>.
    </para>
    
    <para>
      You may also lend copies, under the same conditions stated
      above, and you may publicly display copies.
    </para>
    </sect1>
    
  <sect1 id="fdl-section3">
    <title>3. COPYING IN QUANTITY</title>
    <para>
      If you publish printed copies of the <link
      linkend="fdl-document">Document</link> numbering more than 100,
      and the Document's license notice requires <link
      linkend="fdl-cover-texts">Cover Texts</link>, you must enclose
      the copies in covers that carry, clearly and legibly, all these
      Cover Texts: Front-Cover Texts on the front cover, and
      Back-Cover Texts on the back cover. Both covers must also
      clearly and legibly identify you as the publisher of these
      copies. The front cover must present the full title with all
      words of the title equally prominent and visible. You may add
      other material on the covers in addition. Copying with changes
      limited to the covers, as long as they preserve the title of the
      <link linkend="fdl-document">Document</link> and satisfy these
      conditions, can be treated as verbatim copying in other
      respects.
    </para>
    
    <para>
      If the required texts for either cover are too voluminous to fit
      legibly, you should put the first ones listed (as many as fit
      reasonably) on the actual cover, and continue the rest onto
      adjacent pages.
    </para>
    
    <para>
      If you publish or distribute <link
      linkend="fdl-transparent">Opaque</link> copies of the <link
      linkend="fdl-document">Document</link> numbering more than 100,
      you must either include a machine-readable <link
      linkend="fdl-transparent">Transparent</link> copy along with
      each Opaque copy, or state in or with each Opaque copy a
      publicly-accessible computer-network location containing a
      complete Transparent copy of the Document, free of added
      material, which the general network-using public has access to
      download anonymously at no charge using public-standard network
      protocols. If you use the latter option, you must take
      reasonably prudent steps, when you begin distribution of Opaque
      copies in quantity, to ensure that this Transparent copy will
      remain thus accessible at the stated location until at least one
      year after the last time you distribute an Opaque copy (directly
      or through your agents or retailers) of that edition to the
      public.
    </para>
    
    <para>
      It is requested, but not required, that you contact the authors
      of the <link linkend="fdl-document">Document</link> well before
      redistributing any large number of copies, to give them a chance
      to provide you with an updated version of the Document.
    </para>
    </sect1>
    
  <sect1 id="fdl-section4">
    <title>4. MODIFICATIONS</title>
    <para>
      You may copy and distribute a <link
      linkend="fdl-modified">Modified Version</link> of the <link
      linkend="fdl-document">Document</link> under the conditions of
      sections <link linkend="fdl-section2">2</link> and <link
      linkend="fdl-section3">3</link> above, provided that you release
      the Modified Version under precisely this License, with the
      Modified Version filling the role of the Document, thus
      licensing distribution and modification of the Modified Version
      to whoever possesses a copy of it. In addition, you must do
      these things in the Modified Version:
    </para>
    
    <itemizedlist mark="opencircle">
      <listitem>
	<formalpara>
	  <title>A</title>
	  <para>
	    Use in the <link linkend="fdl-title-page">Title
	    Page</link> (and on the covers, if any) a title distinct
	    from that of the <link
	    linkend="fdl-document">Document</link>, and from those of
	    previous versions (which should, if there were any, be
	    listed in the History section of the Document). You may
	    use the same title as a previous version if the original
	    publisher of that version gives permission.
	  </para>
	</formalpara>
      </listitem>
      
      <listitem>
	<formalpara>
	  <title>B</title>
	  <para>
	    List on the <link linkend="fdl-title-page">Title
	    Page</link>, as authors, one or more persons or entities
	    responsible for authorship of the modifications in the
	    <link linkend="fdl-modified">Modified Version</link>,
	    together with at least five of the principal authors of
	    the <link linkend="fdl-document">Document</link> (all of
	    its principal authors, if it has less than five).
	  </para>
	</formalpara>
      </listitem>
      
      <listitem>
	<formalpara>
	  <title>C</title>
	  <para>
	    State on the <link linkend="fdl-title-page">Title
	    Page</link> the name of the publisher of the <link
	    linkend="fdl-modified">Modified Version</link>, as the
	    publisher.
	  </para>
	</formalpara>
      </listitem>
      
      <listitem>
	<formalpara>
	  <title>D</title>
	  <para>
	    Preserve all the copyright notices of the <link
	    linkend="fdl-document">Document</link>.
	  </para>
	</formalpara>
      </listitem>
      
      <listitem>
	<formalpara>
	  <title>E</title>
	  <para>
	    Add an appropriate copyright notice for your modifications
	    adjacent to the other copyright notices.
	  </para>
	</formalpara>
      </listitem>
      
      <listitem>
	<formalpara>
	  <title>F</title>
	  <para>
	    Include, immediately after the copyright notices, a
	    license notice giving the public permission to use the
	    <link linkend="fdl-modified">Modified Version</link> under
	    the terms of this License, in the form shown in the
	    Addendum below.
	  </para>
	</formalpara>
      </listitem>
      
      <listitem>
	<formalpara>
	  <title>G</title>
	  <para>
	    Preserve in that license notice the full lists of <link
	    linkend="fdl-invariant"> Invariant Sections</link> and
	    required <link linkend="fdl-cover-texts">Cover
	    Texts</link> given in the <link
	    linkend="fdl-document">Document's</link> license notice.
	  </para>
	</formalpara>
      </listitem>
      
      <listitem>
	<formalpara>
	  <title>H</title>
	  <para>
	    Include an unaltered copy of this License.
	  </para>
	</formalpara>
      </listitem>
      
      <listitem>
	<formalpara>
	  <title>I</title>
	  <para>
	    Preserve the section entitled <quote>History</quote>, and
	    its title, and add to it an item stating at least the
	    title, year, new authors, and publisher of the <link
	    linkend="fdl-modified">Modified Version </link>as given on
	    the <link linkend="fdl-title-page">Title Page</link>.  If
	    there is no section entitled <quote>History</quote> in the
	    <link linkend="fdl-document">Document</link>, create one
	    stating the title, year, authors, and publisher of the
	    Document as given on its Title Page, then add an item
	    describing the Modified Version as stated in the previous
	    sentence.
	  </para>
	</formalpara>
      </listitem>
      
      <listitem>
	<formalpara>
	  <title>J</title>
	  <para>
	    Preserve the network location, if any, given in the <link
	    linkend="fdl-document">Document</link> for public access
	    to a <link linkend="fdl-transparent">Transparent</link>
	    copy of the Document, and likewise the network locations
	    given in the Document for previous versions it was based
	    on. These may be placed in the <quote>History</quote>
	    section.  You may omit a network location for a work that
	    was published at least four years before the Document
	    itself, or if the original publisher of the version it
	    refers to gives permission.
	  </para>
	</formalpara>
      </listitem>
      
      <listitem>
	<formalpara>
	  <title>K</title>
	  <para>
	    In any section entitled <quote>Acknowledgements</quote> or
	    <quote>Dedications</quote>, preserve the section's title,
	    and preserve in the section all the substance and tone of
	    each of the contributor acknowledgements and/or
	    dedications given therein.
	  </para>
	</formalpara>
      </listitem>
      
      <listitem>
	<formalpara>
	  <title>L</title>
	  <para>
	    Preserve all the <link linkend="fdl-invariant">Invariant
	    Sections</link> of the <link
	    linkend="fdl-document">Document</link>, unaltered in their
	    text and in their titles.  Section numbers or the
	    equivalent are not considered part of the section titles.
	  </para>
	</formalpara>
      </listitem>
      
      <listitem>
	<formalpara>
	  <title>M</title>
	  <para>
	    Delete any section entitled
	    <quote>Endorsements</quote>. Such a section may not be
	    included in the <link linkend="fdl-modified">Modified
	    Version</link>.
	  </para>
	</formalpara>
      </listitem>
      
      <listitem>
	<formalpara>
	  <title>N</title>
	  <para>
	    Do not retitle any existing section as
	    <quote>Endorsements</quote> or to conflict in title with
	    any <link linkend="fdl-invariant">Invariant
	    Section</link>.
	  </para>
	</formalpara>
      </listitem>
    </itemizedlist>
    
    <para>
      If the <link linkend="fdl-modified">Modified Version</link>
      includes new front-matter sections or appendices that qualify as
      <link linkend="fdl-secondary">Secondary Sections</link> and
      contain no material copied from the Document, you may at your
      option designate some or all of these sections as invariant. To
      do this, add their titles to the list of <link
      linkend="fdl-invariant">Invariant Sections</link> in the
      Modified Version's license notice.  These titles must be
      distinct from any other section titles.
    </para>
    
    <para>
      You may add a section entitled <quote>Endorsements</quote>,
      provided it contains nothing but endorsements of your <link
      linkend="fdl-modified">Modified Version</link> by various
      parties--for example, statements of peer review or that the text
      has been approved by an organization as the authoritative
      definition of a standard.
    </para>
    
    <para>
      You may add a passage of up to five words as a <link
      linkend="fdl-cover-texts">Front-Cover Text</link>, and a passage
      of up to 25 words as a <link
      linkend="fdl-cover-texts">Back-Cover Text</link>, to the end of
      the list of <link linkend="fdl-cover-texts">Cover Texts</link>
      in the <link linkend="fdl-modified">Modified Version</link>.
      Only one passage of Front-Cover Text and one of Back-Cover Text
      may be added by (or through arrangements made by) any one
      entity. If the <link linkend="fdl-document">Document</link>
      already includes a cover text for the same cover, previously
      added by you or by arrangement made by the same entity you are
      acting on behalf of, you may not add another; but you may
      replace the old one, on explicit permission from the previous
      publisher that added the old one.
    </para>
    
    <para>
      The author(s) and publisher(s) of the <link
      linkend="fdl-document">Document</link> do not by this License
      give permission to use their names for publicity for or to
      assert or imply endorsement of any <link
      linkend="fdl-modified">Modified Version </link>.
    </para>
  </sect1>
    
  <sect1 id="fdl-section5">
    <title>5. COMBINING DOCUMENTS</title>
    <para>
      You may combine the <link linkend="fdl-document">Document</link>
      with other documents released under this License, under the
      terms defined in <link linkend="fdl-section4">section 4</link>
      above for modified versions, provided that you include in the
      combination all of the <link linkend="fdl-invariant">Invariant
      Sections</link> of all of the original documents, unmodified,
      and list them all as Invariant Sections of your combined work in
      its license notice.
    </para>
    
    <para>
      The combined work need only contain one copy of this License,
      and multiple identical <link linkend="fdl-invariant">Invariant
      Sections</link> may be replaced with a single copy. If there are
      multiple Invariant Sections with the same name but different
      contents, make the title of each such section unique by adding
      at the end of it, in parentheses, the name of the original
      author or publisher of that section if known, or else a unique
      number. Make the same adjustment to the section titles in the
      list of Invariant Sections in the license notice of the combined
      work.
    </para>
    
    <para>
      In the combination, you must combine any sections entitled
      <quote>History</quote> in the various original documents,
      forming one section entitled <quote>History</quote>; likewise
      combine any sections entitled <quote>Acknowledgements</quote>,
      and any sections entitled <quote>Dedications</quote>.  You must
      delete all sections entitled <quote>Endorsements.</quote>
    </para>
    </sect1>
    
  <sect1 id="fdl-section6">
    <title>6. COLLECTIONS OF DOCUMENTS</title>
    <para>
      You may make a collection consisting of the <link
      linkend="fdl-document">Document</link> and other documents
      released under this License, and replace the individual copies
      of this License in the various documents with a single copy that
      is included in the collection, provided that you follow the
      rules of this License for verbatim copying of each of the
      documents in all other respects.
    </para>
    
    <para>
      You may extract a single document from such a collection, and
      dispbibute it individually under this License, provided you
      insert a copy of this License into the extracted document, and
      follow this License in all other respects regarding verbatim
      copying of that document.
    </para>
    </sect1>
    
  <sect1 id="fdl-section7">
    <title>7. AGGREGATION WITH INDEPENDENT WORKS</title>
    <para>
      A compilation of the <link
      linkend="fdl-document">Document</link> or its derivatives with
      other separate and independent documents or works, in or on a
      volume of a storage or distribution medium, does not as a whole
      count as a <link linkend="fdl-modified">Modified Version</link>
      of the Document, provided no compilation copyright is claimed
      for the compilation.  Such a compilation is called an
      <quote>aggregate</quote>, and this License does not apply to the
      other self-contained works thus compiled with the Document , on
      account of their being thus compiled, if they are not themselves
      derivative works of the Document.  If the <link
      linkend="fdl-cover-texts">Cover Text</link> requirement of <link
      linkend="fdl-section3">section 3</link> is applicable to these
      copies of the Document, then if the Document is less than one
      quarter of the entire aggregate, the Document's Cover Texts may
      be placed on covers that surround only the Document within the
      aggregate. Otherwise they must appear on covers around the whole
      aggregate.
    </para>
    </sect1>
    
  <sect1 id="fdl-section8">
    <title>8. TRANSLATION</title>
    <para>
      Translation is considered a kind of modification, so you may
      distribute translations of the <link
      linkend="fdl-document">Document</link> under the terms of <link
      linkend="fdl-section4">section 4</link>. Replacing <link
      linkend="fdl-invariant"> Invariant Sections</link> with
      translations requires special permission from their copyright
      holders, but you may include translations of some or all
      Invariant Sections in addition to the original versions of these
      Invariant Sections. You may include a translation of this
      License provided that you also include the original English
      version of this License. In case of a disagreement between the
      translation and the original English version of this License,
      the original English version will prevail.
    </para>
    </sect1>
    
  <sect1 id="fdl-section9">
    <title>9. TERMINATION</title>
    <para>
      You may not copy, modify, sublicense, or distribute the <link
      linkend="fdl-document">Document</link> except as expressly
      provided for under this License. Any other attempt to copy,
      modify, sublicense or distribute the Document is void, and will
      automatically terminate your rights under this License. However,
      parties who have received copies, or rights, from you under this
      License will not have their licenses terminated so long as such
      parties remain in full compliance.
    </para>
    </sect1>
    
  <sect1 id="fdl-section10">
    <title>10. FUTURE REVISIONS OF THIS LICENSE</title>
    <para>
      The <ulink type="http"
      url="http://www.gnu.org/fsf/fsf.html">Free Software
      Foundation</ulink> may publish new, revised versions of the GNU
      Free Documentation License from time to time. Such new versions
      will be similar in spirit to the present version, but may differ
      in detail to address new problems or concerns. See <ulink
      type="http"
      url="http://www.gnu.org/copyleft">http://www.gnu.org/copyleft/</ulink>.
    </para>
    
    <para>
      Each version of the License is given a distinguishing version
      number. If the <link linkend="fdl-document">Document</link>
      specifies that a particular numbered version of this License
      <quote>or any later version</quote> applies to it, you have the
      option of following the terms and conditions either of that
      specified version or of any later version that has been
      published (not as a draft) by the Free Software Foundation. If
      the Document does not specify a version number of this License,
      you may choose any version ever published (not as a draft) by
      the Free Software Foundation.
    </para>
  </sect1>

  <sect1 id="fdl-using">
    <title>Addendum</title>
    <para>
      To use this License in a document you have written, include a copy of
      the License in the document and put the following copyright and
      license notices just after the title page:
    </para>
    
    <blockquote>
      <para>
	Copyright &copy; YEAR YOUR NAME.
      </para>
      <para>
	Permission is granted to copy, distribute and/or modify this
	document under the terms of the GNU Free Documentation
	License, Version 1.1 or any later version published by the
	Free Software Foundation; with the <link
	linkend="fdl-invariant">Invariant Sections</link> being LIST
	THEIR TITLES, with the <link
	linkend="fdl-cover-texts">Front-Cover Texts</link> being LIST,
	and with the <link linkend="fdl-cover-texts">Back-Cover
	Texts</link> being LIST.  A copy of the license is included in
	the section entitled <quote>GNU Free Documentation
	License</quote>.
      </para>
    </blockquote>
      
    <para>
      If you have no <link linkend="fdl-invariant">Invariant
      Sections</link>, write <quote>with no Invariant Sections</quote>
      instead of saying which ones are invariant.  If you have no
      <link linkend="fdl-cover-texts">Front-Cover Texts</link>, write
      <quote>no Front-Cover Texts</quote> instead of
      <quote>Front-Cover Texts being LIST</quote>; likewise for <link
      linkend="fdl-cover-texts">Back-Cover Texts</link>.
    </para>
    
    <para>
      If your document contains nontrivial examples of program code,
      we recommend releasing these examples in parallel under your
      choice of free software license, such as the <ulink type="http"
      url="http://www.gnu.org/copyleft/gpl.html"> GNU General Public
      License</ulink>, to permit their use in free software.
    </para>
  </sect1>
</chapter>