1 GNU Free Documentation License
2 Version 1.3, 3 November 2008
5 Copyright (C) 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.
7 Everyone is permitted to copy and distribute verbatim copies
8 of this license document, but changing it is not allowed.
12 The purpose of this License is to make a manual, textbook, or other
13 functional and useful document "free" in the sense of freedom: to
14 assure everyone the effective freedom to copy and redistribute it,
15 with or without modifying it, either commercially or noncommercially.
16 Secondarily, this License preserves for the author and publisher a way
17 to get credit for their work, while not being considered responsible
18 for modifications made by others.
20 This License is a kind of "copyleft", which means that derivative
21 works of the document must themselves be free in the same sense. It
22 complements the GNU General Public License, which is a copyleft
23 license designed for free software.
25 We have designed this License in order to use it for manuals for free
26 software, because free software needs free documentation: a free
27 program should come with manuals providing the same freedoms that the
28 software does. But this License is not limited to software manuals;
29 it can be used for any textual work, regardless of subject matter or
30 whether it is published as a printed book. We recommend this License
31 principally for works whose purpose is instruction or reference.
34 1. APPLICABILITY AND DEFINITIONS
36 This License applies to any manual or other work, in any medium, that
37 contains a notice placed by the copyright holder saying it can be
38 distributed under the terms of this License. Such a notice grants a
39 world-wide, royalty-free license, unlimited in duration, to use that
40 work under the conditions stated herein. The "Document", below,
41 refers to any such manual or work. Any member of the public is a
42 licensee, and is addressed as "you". You accept the license if you
43 copy, modify or distribute the work in a way requiring permission
46 A "Modified Version" of the Document means any work containing the
47 Document or a portion of it, either copied verbatim, or with
48 modifications and/or translated into another language.
50 A "Secondary Section" is a named appendix or a front-matter section of
51 the Document that deals exclusively with the relationship of the
52 publishers or authors of the Document to the Document's overall
53 subject (or to related matters) and contains nothing that could fall
54 directly within that overall subject. (Thus, if the Document is in
55 part a textbook of mathematics, a Secondary Section may not explain
56 any mathematics.) The relationship could be a matter of historical
57 connection with the subject or with related matters, or of legal,
58 commercial, philosophical, ethical or political position regarding
61 The "Invariant Sections" are certain Secondary Sections whose titles
62 are designated, as being those of Invariant Sections, in the notice
63 that says that the Document is released under this License. If a
64 section does not fit the above definition of Secondary then it is not
65 allowed to be designated as Invariant. The Document may contain zero
66 Invariant Sections. If the Document does not identify any Invariant
67 Sections then there are none.
69 The "Cover Texts" are certain short passages of text that are listed,
70 as Front-Cover Texts or Back-Cover Texts, in the notice that says that
71 the Document is released under this License. A Front-Cover Text may
72 be at most 5 words, and a Back-Cover Text may be at most 25 words.
74 A "Transparent" copy of the Document means a machine-readable copy,
75 represented in a format whose specification is available to the
76 general public, that is suitable for revising the document
77 straightforwardly with generic text editors or (for images composed of
78 pixels) generic paint programs or (for drawings) some widely available
79 drawing editor, and that is suitable for input to text formatters or
80 for automatic translation to a variety of formats suitable for input
81 to text formatters. A copy made in an otherwise Transparent file
82 format whose markup, or absence of markup, has been arranged to thwart
83 or discourage subsequent modification by readers is not Transparent.
84 An image format is not Transparent if used for any substantial amount
85 of text. A copy that is not "Transparent" is called "Opaque".
87 Examples of suitable formats for Transparent copies include plain
88 ASCII without markup, Texinfo input format, LaTeX input format, SGML
89 or XML using a publicly available DTD, and standard-conforming simple
90 HTML, PostScript or PDF designed for human modification. Examples of
91 transparent image formats include PNG, XCF and JPG. Opaque formats
92 include proprietary formats that can be read and edited only by
93 proprietary word processors, SGML or XML for which the DTD and/or
94 processing tools are not generally available, and the
95 machine-generated HTML, PostScript or PDF produced by some word
96 processors for output purposes only.
98 The "Title Page" means, for a printed book, the title page itself,
99 plus such following pages as are needed to hold, legibly, the material
100 this License requires to appear in the title page. For works in
101 formats which do not have any title page as such, "Title Page" means
102 the text near the most prominent appearance of the work's title,
103 preceding the beginning of the body of the text.
105 The "publisher" means any person or entity that distributes copies of
106 the Document to the public.
108 A section "Entitled XYZ" means a named subunit of the Document whose
109 title either is precisely XYZ or contains XYZ in parentheses following
110 text that translates XYZ in another language. (Here XYZ stands for a
111 specific section name mentioned below, such as "Acknowledgements",
112 "Dedications", "Endorsements", or "History".) To "Preserve the Title"
113 of such a section when you modify the Document means that it remains a
114 section "Entitled XYZ" according to this definition.
116 The Document may include Warranty Disclaimers next to the notice which
117 states that this License applies to the Document. These Warranty
118 Disclaimers are considered to be included by reference in this
119 License, but only as regards disclaiming warranties: any other
120 implication that these Warranty Disclaimers may have is void and has
121 no effect on the meaning of this License.
125 You may copy and distribute the Document in any medium, either
126 commercially or noncommercially, provided that this License, the
127 copyright notices, and the license notice saying this License applies
128 to the Document are reproduced in all copies, and that you add no
129 other conditions whatsoever to those of this License. You may not use
130 technical measures to obstruct or control the reading or further
131 copying of the copies you make or distribute. However, you may accept
132 compensation in exchange for copies. If you distribute a large enough
133 number of copies you must also follow the conditions in section 3.
135 You may also lend copies, under the same conditions stated above, and
136 you may publicly display copies.
139 3. COPYING IN QUANTITY
141 If you publish printed copies (or copies in media that commonly have
142 printed covers) of the Document, numbering more than 100, and the
143 Document's license notice requires Cover Texts, you must enclose the
144 copies in covers that carry, clearly and legibly, all these Cover
145 Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on
146 the back cover. Both covers must also clearly and legibly identify
147 you as the publisher of these copies. The front cover must present
148 the full title with all words of the title equally prominent and
149 visible. You may add other material on the covers in addition.
150 Copying with changes limited to the covers, as long as they preserve
151 the title of the Document and satisfy these conditions, can be treated
152 as verbatim copying in other respects.
154 If the required texts for either cover are too voluminous to fit
155 legibly, you should put the first ones listed (as many as fit
156 reasonably) on the actual cover, and continue the rest onto adjacent
159 If you publish or distribute Opaque copies of the Document numbering
160 more than 100, you must either include a machine-readable Transparent
161 copy along with each Opaque copy, or state in or with each Opaque copy
162 a computer-network location from which the general network-using
163 public has access to download using public-standard network protocols
164 a complete Transparent copy of the Document, free of added material.
165 If you use the latter option, you must take reasonably prudent steps,
166 when you begin distribution of Opaque copies in quantity, to ensure
167 that this Transparent copy will remain thus accessible at the stated
168 location until at least one year after the last time you distribute an
169 Opaque copy (directly or through your agents or retailers) of that
170 edition to the public.
172 It is requested, but not required, that you contact the authors of the
173 Document well before redistributing any large number of copies, to
174 give them a chance to provide you with an updated version of the
180 You may copy and distribute a Modified Version of the Document under
181 the conditions of sections 2 and 3 above, provided that you release
182 the Modified Version under precisely this License, with the Modified
183 Version filling the role of the Document, thus licensing distribution
184 and modification of the Modified Version to whoever possesses a copy
185 of it. In addition, you must do these things in the Modified Version:
187 A. Use in the Title Page (and on the covers, if any) a title distinct
188 from that of the Document, and from those of previous versions
189 (which should, if there were any, be listed in the History section
190 of the Document). You may use the same title as a previous version
191 if the original publisher of that version gives permission.
192 B. List on the Title Page, as authors, one or more persons or entities
193 responsible for authorship of the modifications in the Modified
194 Version, together with at least five of the principal authors of the
195 Document (all of its principal authors, if it has fewer than five),
196 unless they release you from this requirement.
197 C. State on the Title page the name of the publisher of the
198 Modified Version, as the publisher.
199 D. Preserve all the copyright notices of the Document.
200 E. Add an appropriate copyright notice for your modifications
201 adjacent to the other copyright notices.
202 F. Include, immediately after the copyright notices, a license notice
203 giving the public permission to use the Modified Version under the
204 terms of this License, in the form shown in the Addendum below.
205 G. Preserve in that license notice the full lists of Invariant Sections
206 and required Cover Texts given in the Document's license notice.
207 H. Include an unaltered copy of this License.
208 I. Preserve the section Entitled "History", Preserve its Title, and add
209 to it an item stating at least the title, year, new authors, and
210 publisher of the Modified Version as given on the Title Page. If
211 there is no section Entitled "History" in the Document, create one
212 stating the title, year, authors, and publisher of the Document as
213 given on its Title Page, then add an item describing the Modified
214 Version as stated in the previous sentence.
215 J. Preserve the network location, if any, given in the Document for
216 public access to a Transparent copy of the Document, and likewise
217 the network locations given in the Document for previous versions
218 it was based on. These may be placed in the "History" section.
219 You may omit a network location for a work that was published at
220 least four years before the Document itself, or if the original
221 publisher of the version it refers to gives permission.
222 K. For any section Entitled "Acknowledgements" or "Dedications",
223 Preserve the Title of the section, and preserve in the section all
224 the substance and tone of each of the contributor acknowledgements
225 and/or dedications given therein.
226 L. Preserve all the Invariant Sections of the Document,
227 unaltered in their text and in their titles. Section numbers
228 or the equivalent are not considered part of the section titles.
229 M. Delete any section Entitled "Endorsements". Such a section
230 may not be included in the Modified Version.
231 N. Do not retitle any existing section to be Entitled "Endorsements"
232 or to conflict in title with any Invariant Section.
233 O. Preserve any Warranty Disclaimers.
235 If the Modified Version includes new front-matter sections or
236 appendices that qualify as Secondary Sections and contain no material
237 copied from the Document, you may at your option designate some or all
238 of these sections as invariant. To do this, add their titles to the
239 list of Invariant Sections in the Modified Version's license notice.
240 These titles must be distinct from any other section titles.
242 You may add a section Entitled "Endorsements", provided it contains
243 nothing but endorsements of your Modified Version by various
244 parties--for example, statements of peer review or that the text has
245 been approved by an organization as the authoritative definition of a
248 You may add a passage of up to five words as a Front-Cover Text, and a
249 passage of up to 25 words as a Back-Cover Text, to the end of the list
250 of Cover Texts in the Modified Version. Only one passage of
251 Front-Cover Text and one of Back-Cover Text may be added by (or
252 through arrangements made by) any one entity. If the Document already
253 includes a cover text for the same cover, previously added by you or
254 by arrangement made by the same entity you are acting on behalf of,
255 you may not add another; but you may replace the old one, on explicit
256 permission from the previous publisher that added the old one.
258 The author(s) and publisher(s) of the Document do not by this License
259 give permission to use their names for publicity for or to assert or
260 imply endorsement of any Modified Version.
263 5. COMBINING DOCUMENTS
265 You may combine the Document with other documents released under this
266 License, under the terms defined in section 4 above for modified
267 versions, provided that you include in the combination all of the
268 Invariant Sections of all of the original documents, unmodified, and
269 list them all as Invariant Sections of your combined work in its
270 license notice, and that you preserve all their Warranty Disclaimers.
272 The combined work need only contain one copy of this License, and
273 multiple identical Invariant Sections may be replaced with a single
274 copy. If there are multiple Invariant Sections with the same name but
275 different contents, make the title of each such section unique by
276 adding at the end of it, in parentheses, the name of the original
277 author or publisher of that section if known, or else a unique number.
278 Make the same adjustment to the section titles in the list of
279 Invariant Sections in the license notice of the combined work.
281 In the combination, you must combine any sections Entitled "History"
282 in the various original documents, forming one section Entitled
283 "History"; likewise combine any sections Entitled "Acknowledgements",
284 and any sections Entitled "Dedications". You must delete all sections
285 Entitled "Endorsements".
288 6. COLLECTIONS OF DOCUMENTS
290 You may make a collection consisting of the Document and other
291 documents released under this License, and replace the individual
292 copies of this License in the various documents with a single copy
293 that is included in the collection, provided that you follow the rules
294 of this License for verbatim copying of each of the documents in all
297 You may extract a single document from such a collection, and
298 distribute it individually under this License, provided you insert a
299 copy of this License into the extracted document, and follow this
300 License in all other respects regarding verbatim copying of that
304 7. AGGREGATION WITH INDEPENDENT WORKS
306 A compilation of the Document or its derivatives with other separate
307 and independent documents or works, in or on a volume of a storage or
308 distribution medium, is called an "aggregate" if the copyright
309 resulting from the compilation is not used to limit the legal rights
310 of the compilation's users beyond what the individual works permit.
311 When the Document is included in an aggregate, this License does not
312 apply to the other works in the aggregate which are not themselves
313 derivative works of the Document.
315 If the Cover Text requirement of section 3 is applicable to these
316 copies of the Document, then if the Document is less than one half of
317 the entire aggregate, the Document's Cover Texts may be placed on
318 covers that bracket the Document within the aggregate, or the
319 electronic equivalent of covers if the Document is in electronic form.
320 Otherwise they must appear on printed covers that bracket the whole
326 Translation is considered a kind of modification, so you may
327 distribute translations of the Document under the terms of section 4.
328 Replacing Invariant Sections with translations requires special
329 permission from their copyright holders, but you may include
330 translations of some or all Invariant Sections in addition to the
331 original versions of these Invariant Sections. You may include a
332 translation of this License, and all the license notices in the
333 Document, and any Warranty Disclaimers, provided that you also include
334 the original English version of this License and the original versions
335 of those notices and disclaimers. In case of a disagreement between
336 the translation and the original version of this License or a notice
337 or disclaimer, the original version will prevail.
339 If a section in the Document is Entitled "Acknowledgements",
340 "Dedications", or "History", the requirement (section 4) to Preserve
341 its Title (section 1) will typically require changing the actual
347 You may not copy, modify, sublicense, or distribute the Document
348 except as expressly provided under this License. Any attempt
349 otherwise to copy, modify, sublicense, or distribute it is void, and
350 will automatically terminate your rights under this License.
352 However, if you cease all violation of this License, then your license
353 from a particular copyright holder is reinstated (a) provisionally,
354 unless and until the copyright holder explicitly and finally
355 terminates your license, and (b) permanently, if the copyright holder
356 fails to notify you of the violation by some reasonable means prior to
357 60 days after the cessation.
359 Moreover, your license from a particular copyright holder is
360 reinstated permanently if the copyright holder notifies you of the
361 violation by some reasonable means, this is the first time you have
362 received notice of violation of this License (for any work) from that
363 copyright holder, and you cure the violation prior to 30 days after
364 your receipt of the notice.
366 Termination of your rights under this section does not terminate the
367 licenses of parties who have received copies or rights from you under
368 this License. If your rights have been terminated and not permanently
369 reinstated, receipt of a copy of some or all of the same material does
370 not give you any rights to use it.
373 10. FUTURE REVISIONS OF THIS LICENSE
375 The Free Software Foundation may publish new, revised versions of the
376 GNU Free Documentation License from time to time. Such new versions
377 will be similar in spirit to the present version, but may differ in
378 detail to address new problems or concerns. See
379 http://www.gnu.org/copyleft/.
381 Each version of the License is given a distinguishing version number.
382 If the Document specifies that a particular numbered version of this
383 License "or any later version" applies to it, you have the option of
384 following the terms and conditions either of that specified version or
385 of any later version that has been published (not as a draft) by the
386 Free Software Foundation. If the Document does not specify a version
387 number of this License, you may choose any version ever published (not
388 as a draft) by the Free Software Foundation. If the Document
389 specifies that a proxy can decide which future versions of this
390 License can be used, that proxy's public statement of acceptance of a
391 version permanently authorizes you to choose that version for the
396 "Massive Multiauthor Collaboration Site" (or "MMC Site") means any
397 World Wide Web server that publishes copyrightable works and also
398 provides prominent facilities for anybody to edit those works. A
399 public wiki that anybody can edit is an example of such a server. A
400 "Massive Multiauthor Collaboration" (or "MMC") contained in the site
401 means any set of copyrightable works thus published on the MMC site.
403 "CC-BY-SA" means the Creative Commons Attribution-Share Alike 3.0
404 license published by Creative Commons Corporation, a not-for-profit
405 corporation with a principal place of business in San Francisco,
406 California, as well as future copyleft versions of that license
407 published by that same organization.
409 "Incorporate" means to publish or republish a Document, in whole or in
410 part, as part of another Document.
412 An MMC is "eligible for relicensing" if it is licensed under this
413 License, and if all works that were first published under this License
414 somewhere other than this MMC, and subsequently incorporated in whole or
415 in part into the MMC, (1) had no cover texts or invariant sections, and
416 (2) were thus incorporated prior to November 1, 2008.
418 The operator of an MMC Site may republish an MMC contained in the site
419 under CC-BY-SA on the same site at any time before August 1, 2009,
420 provided the MMC is eligible for relicensing.
423 ADDENDUM: How to use this License for your documents
425 To use this License in a document you have written, include a copy of
426 the License in the document and put the following copyright and
427 license notices just after the title page:
429 Copyright (c) YEAR YOUR NAME.
430 Permission is granted to copy, distribute and/or modify this document
431 under the terms of the GNU Free Documentation License, Version 1.3
432 or any later version published by the Free Software Foundation;
433 with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
434 A copy of the license is included in the section entitled "GNU
435 Free Documentation License".
437 If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts,
438 replace the "with...Texts." line with this:
440 with the Invariant Sections being LIST THEIR TITLES, with the
441 Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST.
443 If you have Invariant Sections without Cover Texts, or some other
444 combination of the three, merge those two alternatives to suit the
447 If your document contains nontrivial examples of program code, we
448 recommend releasing these examples in parallel under your choice of
449 free software license, such as the GNU General Public License,
450 to permit their use in free software.