gnu free documentation license

GNU Free Documentation License
GFDL

   <legal> (GFDL) The {Free Software Foundation}'s license
   designed to ensure the same freedoms for {documentation} that
   the {GPL} gives to {software}.

   This dictionary is distributed under the GFDL, see the
   copyright notice in the {Free On-line Dictionary of Computing}
   section (at the start of the source file).  The full text
   follows.

   Version 1.1, March 2000

   Copyright (C) 2000 Free Software Foundation, Inc.

   59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

   Everyone is permitted to copy and distribute verbatim copies
   of this license document, but changing it is not allowed.

   0. PREAMBLE

   The purpose of this License is to make a manual, textbook, or
   other written document "free" 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.

   This License is a kind of "copyleft", 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.

   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.

   1. APPLICABILITY AND DEFINITIONS

   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 "Document",
   below, refers to any such manual or work.  Any member of the
   public is a licensee, and is addressed as "you".

   A "Modified Version" 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.

   A "Secondary Section" is a named appendix or a front-matter
   section of the Document 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.

   The "Invariant Sections" are certain Secondary Sections whose
   titles are designated, as being those of Invariant Sections,
   in the notice that says that the Document is released under
   this License.

   The "Cover Texts" are certain short passages of text that are
   listed, as Front-Cover Texts or Back-Cover Texts, in the
   notice that says that the Document is released under this
   License.

   A "Transparent" copy of the Document 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 "Transparent" is called "Opaque".

   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.

   The "Title Page" 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, "Title Page" means the text near the most
   prominent appearance of the work's title, preceding the
   beginning of the body of the text.

   2. VERBATIM COPYING

   You may copy and distribute the Document 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 section 3.

   You may also lend copies, under the same conditions stated
   above, and you may publicly display copies.

   3. COPYING IN QUANTITY

   If you publish printed copies of the Document numbering more
   than 100, and the Document's license notice requires Cover
   Texts, 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 Document and satisfy these
   conditions, can be treated as verbatim copying in other
   respects.

   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.

   If you publish or distribute Opaque copies of the Document
   numbering more than 100, you must either include a
   machine-readable Transparent 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.

   It is requested, but not required, that you contact the
   authors of the Document well before redistributing any large
   number of copies, to give them a chance to provide you with an
   updated version of the Document.

   4. MODIFICATIONS

   You may copy and distribute a Modified Version of the Document
   under the conditions of sections 2 and 3 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:

   A. Use in the Title Page (and on the covers, if any) a title
   distinct from that of the Document, 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.

   B. List on the Title Page, as authors, one or more persons or
   entities responsible for authorship of the modifications in
   the Modified Version, together with at least five of the
   principal authors of the Document (all of its principal
   authors, if it has less than five).

   C. State on the Title page the name of the publisher of the
   Modified Version, as the publisher.

   D. Preserve all the copyright notices of the Document.

   E. Add an appropriate copyright notice for your modifications
   adjacent to the other copyright notices.

   F. Include, immediately after the copyright notices, a license
   notice giving the public permission to use the Modified
   Version under the terms of this License, in the form shown in
   the Addendum below.

   G. Preserve in that license notice the full lists of Invariant
   Sections and required Cover Texts given in the Document's
   license notice.

   H. Include an unaltered copy of this License.

   I. Preserve the section entitled "History", and its title, and
   add to it an item stating at least the title, year, new
   authors, and publisher of the Modified Version as given on the
   Title Page. If there is no section entitled "History" in the
   Document, 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.

   J. Preserve the network location, if any, given in the
   Document for public access to a Transparent 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 "History" 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.

   K. In any section entitled "Acknowledgements" or
   "Dedications", 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.

   L. Preserve all the Invariant Sections of the Document,
   unaltered in their text and in their titles. Section numbers
   or the equivalent are not considered part of the section
   titles.

   M. Delete any section entitled "Endorsements".  Such a section
   may not be included in the Modified Version.

   N. Do not retitle any existing section as "Endorsements" or to
   conflict in title with any Invariant Section.  If the Modified
   Version includes new front-matter sections or appendices that
   qualify as Secondary Sections 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 Invariant Sections in the Modified
   Version's license notice.  These titles must be distinct from
   any other section titles.

   You may add a section entitled "Endorsements", provided it
   contains nothing but endorsements of your Modified Version 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.

   You may add a passage of up to five words as a Front-Cover
   Text, and a passage of up to 25 words as a Back-Cover Text, to
   the end of the list of Cover Texts in the Modified
   Version.  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 Document 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.

   The author(s) and publisher(s) of the Document do not by this
   License give permission to use their names for publicity for
   or to assert or imply endorsement of any Modified Version.

   5. COMBINING DOCUMENTS

   You may combine the Document with other documents released
   under this License, under the terms defined in section 4 above
   for modified versions, provided that you include in the
   combination all of the Invariant Sections of all of the
   original documents, unmodified, and list them all as Invariant
   Sections of your combined work in its license notice.

   The combined work need only contain one copy of this License,
   and multiple identical Invariant Sections 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.

   In the combination, you must combine any sections entitled
   "History" in the various original documents, forming one
   section entitled "History"; likewise combine any sections
   entitled "Acknowledgements", and any sections entitled
   "Dedications". You must delete all sections entitled
   "Endorsements."

   6. COLLECTIONS OF DOCUMENTS

   You may make a collection consisting of the Document 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.

   You may extract a single document from such a collection, and
   distribute 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.

   7. AGGREGATION WITH INDEPENDENT WORKS

   A compilation of the Document 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 Modified Version of the Document, provided no compilation
   copyright is claimed for the compilation.  Such a compilation
   is called an "aggregate", 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 Cover Text requirement of section 3 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.

   8. TRANSLATION

   Translation is considered a kind of modification, so you may
   distribute translations of the Document under the terms of
   section 4.  Replacing Invariant Sections 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.

   9. TERMINATION

   You may not copy, modify, sublicense, or distribute the
   Document 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.

   10. FUTURE REVISIONS OF THIS LICENSE

   The Free Software Foundation 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 here (http://gnu.org/copyleft/).

   Each version of the License is given a distinguishing version
   number.  If the Document specifies that a particular numbered
   version of this License "or any later version" 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.

   End of full text of GFDL.

   (2002-03-09)