1The LaTeX Project Public License
2
3=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
4
5LPPL Version 1.3c 2008-05-04 Copyright 1999 2002-2008 LaTeX3 Project
6
7Everyone is allowed to distribute verbatim copies of this license document,
8but modification of it is not allowed.
9
10PREAMBLE
11
12========
13
14The LaTeX Project Public License (LPPL) is the primary license under which
15the LaTeX kernel and the base LaTeX packages are distributed.
16
17You may use this license for any work of which you hold the copyright and
18which you wish to distribute. This license may be particularly suitable if
19your work is TeX-related (such as a LaTeX package), but it is written in such
20a way that you can use it even if your work is unrelated to TeX.
21
22The section `WHETHER AND HOW TO DISTRIBUTE WORKS UNDER THIS LICENSE', below,
23gives instructions, examples, and recommendations for authors who are considering
24distributing their works under this license.
25
26This license gives conditions under which a work may be distributed and modified,
27as well as conditions under which modified versions of that work may be distributed.
28
29We, the LaTeX3 Project, believe that the conditions below give you the freedom
30to make and distribute modified versions of your work that conform with whatever
31technical specifications you wish while maintaining the availability, integrity,
32and reliability of that work. If you do not see how to achieve your goal while
33meeting these conditions, then read the document `cfgguide.tex' and `modguide.tex'
34in the base LaTeX distribution for suggestions.
35
36DEFINITIONS
37
38===========
39
40In this license document the following terms are used:
41
42`Work' Any work being distributed under this License. `Derived Work' Any work
43that under any applicable law is derived from the Work.
44
45`Modification' Any procedure that produces a Derived Work under any applicable
46law -- for example, the production of a file containing an original file associated
47with the Work or a significant portion of such a file, either verbatim or
48with modifications and/or translated into another language.
49
50`Modify' To apply any procedure that produces a Derived Work under any applicable
51law. `Distribution' Making copies of the Work available from one person to
52another, in whole or in part. Distribution includes (but is not limited to)
53making any electronic components of the Work accessible by file transfer protocols
54such as FTP or HTTP or by shared file systems such as Sun's Network File System
55(NFS).
56
57`Compiled Work' A version of the Work that has been processed into a form
58where it is directly usable on a computer system. This processing may include
59using installation facilities provided by the Work, transformations of the
60Work, copying of components of the Work, or other activities. Note that modification
61of any installation facilities provided by the Work constitutes modification
62of the Work.
63
64`Current Maintainer' A person or persons nominated as such within the Work.
65If there is no such explicit nomination then it is the `Copyright Holder'
66under any applicable law.
67
68`Base Interpreter' A program or process that is normally needed for running
69or interpreting a part or the whole of the Work.
70
71A Base Interpreter may depend on external components but these are not considered
72part of the Base Interpreter provided that each external component clearly
73identifies itself whenever it is used interactively. Unless explicitly specified
74when applying the license to the Work, the only applicable Base Interpreter
75is a `LaTeX-Format' or in the case of files belonging to the `LaTeX-format'
76a program implementing the `TeX language'.
77
78CONDITIONS ON DISTRIBUTION AND MODIFICATION
79
80===========================================
81
821. Activities other than distribution and/or modification of the Work are
83not covered by this license; they are outside its scope. In particular, the
84act of running the Work is not restricted and no requirements are made concerning
85any offers of support for the Work.
86
872. You may distribute a complete, unmodified copy of the Work as you received
88it. Distribution of only part of the Work is considered modification of the
89Work, and no right to distribute such a Derived Work may be assumed under
90the terms of this clause.
91
923. You may distribute a Compiled Work that has been generated from a complete,
93unmodified copy of the Work as distributed under Clause 2 above, as long as
94that Compiled Work is distributed in such a way that the recipients may install
95the Compiled Work on their system exactly as it would have been installed
96if they generated a Compiled Work directly from the Work.
97
984. If you are the Current Maintainer of the Work, you may, without restriction,
99modify the Work, thus creating a Derived Work. You may also distribute the
100Derived Work without restriction, including Compiled Works generated from
101the Derived Work. Derived Works distributed in this manner by the Current
102Maintainer are considered to be updated versions of the Work.
103
1045. If you are not the Current Maintainer of the Work, you may modify your
105copy of the Work, thus creating a Derived Work based on the Work, and compile
106this Derived Work, thus creating a Compiled Work based on the Derived Work.
107
1086. If you are not the Current Maintainer of the Work, you may distribute a
109Derived Work provided the following conditions are met for every component
110of the Work unless that component clearly states in the copyright notice that
111it is exempt from that condition. Only the Current Maintainer is allowed to
112add such statements of exemption to a component of the Work.
113
114a. If a component of this Derived Work can be a direct replacement for a component
115of the Work when that component is used with the Base Interpreter, then, wherever
116this component of the Work identifies itself to the user when used interactively
117with that Base Interpreter, the replacement component of this Derived Work
118clearly and unambiguously identifies itself as a modified version of this
119component to the user when used interactively with that Base Interpreter.
120
121b. Every component of the Derived Work contains prominent notices detailing
122the nature of the changes to that component, or a prominent reference to another
123file that is distributed as part of the Derived Work and that contains a complete
124and accurate log of the changes.
125
126c. No information in the Derived Work implies that any persons, including
127(but not limited to) the authors of the original version of the Work, provide
128any support, including (but not limited to) the reporting and handling of
129errors, to recipients of the Derived Work unless those persons have stated
130explicitly that they do provide such support for the Derived Work.
131
132      d. You distribute at least one of the following with the Derived Work:
133
1341. A complete, unmodified copy of the Work; if your distribution of a modified
135component is made by offering access to copy the modified component from a
136designated place, then offering equivalent access to copy the Work from the
137same or some similar place meets this condition, even though third parties
138are not compelled to copy the Work along with the modified component;
139
1402. Information that is sufficient to obtain a complete, unmodified copy of
141the Work.
142
1437. If you are not the Current Maintainer of the Work, you may distribute a
144Compiled Work generated from a Derived Work, as long as the Derived Work is
145distributed to all recipients of the Compiled Work, and as long as the conditions
146of Clause 6, above, are met with regard to the Derived Work.
147
1488. The conditions above are not intended to prohibit, and hence do not apply
149to, the modification, by any method, of any component so that it becomes identical
150to an updated version of that component of the Work as it is distributed by
151the Current Maintainer under Clause 4, above.
152
1539. Distribution of the Work or any Derived Work in an alternative format,
154where the Work or that Derived Work (in whole or in part) is then produced
155by applying some process to that format, does not relax or nullify any sections
156of this license as they pertain to the results of applying that process.
157
158   10.
159
160a. A Derived Work may be distributed under a different license provided that
161license itself honors the conditions listed in Clause 6 above, in regard to
162the Work, though it does not have to honor the rest of the conditions in this
163license.
164
165b. If a Derived Work is distributed under a different license, that Derived
166Work must provide sufficient documentation as part of itself to allow each
167recipient of that Derived Work to honor the restrictions in Clause 6 above,
168concerning changes from the Work.
169
17011. This license places no restrictions on works that are unrelated to the
171Work, nor does this license place any restrictions on aggregating such works
172with the Work by any means.
173
17412. Nothing in this license is intended to, or may be used to, prevent complete
175compliance by all parties with all applicable laws.
176
177NO WARRANTY
178
179===========
180
181There is no warranty for the Work. Except when otherwise stated in writing,
182the Copyright Holder provides the Work `as is', without warranty of any kind,
183either expressed or implied, including, but not limited to, the implied warranties
184of merchantability and fitness for a particular purpose. The entire risk as
185to the quality and performance of the Work is with you. Should the Work prove
186defective, you assume the cost of all necessary servicing, repair, or correction.
187
188In no event unless required by applicable law or agreed to in writing will
189The Copyright Holder, or any author named in the components of the Work, or
190any other party who may distribute and/or modify the Work as permitted above,
191be liable to you for damages, including any general, special, incidental or
192consequential damages arising out of any use of the Work or out of inability
193to use the Work (including, but not limited to, loss of data, data being rendered
194inaccurate, or losses sustained by anyone as a result of any failure of the
195Work to operate with any other programs), even if the Copyright Holder or
196said author or said other party has been advised of the possibility of such
197damages.
198
199MAINTENANCE OF THE WORK
200
201=======================
202
203The Work has the status `author-maintained' if the Copyright Holder explicitly
204and prominently states near the primary copyright notice in the Work that
205the Work can only be maintained by the Copyright Holder or simply that it
206is `author-maintained'.
207
208The Work has the status `maintained' if there is a Current Maintainer who
209has indicated in the Work that they are willing to receive error reports for
210the Work (for example, by supplying a valid e-mail address). It is not required
211for the Current Maintainer to acknowledge or act upon these error reports.
212
213The Work changes from status `maintained' to `unmaintained' if there is no
214Current Maintainer, or the person stated to be Current Maintainer of the work
215cannot be reached through the indicated means of communication for a period
216of six months, and there are no other significant signs of active maintenance.
217
218You can become the Current Maintainer of the Work by agreement with any existing
219Current Maintainer to take over this role.
220
221If the Work is unmaintained, you can become the Current Maintainer of the
222Work through the following steps:
223
2241. Make a reasonable attempt to trace the Current Maintainer (and the Copyright
225Holder, if the two differ) through the means of an Internet or similar search.
226
2272. If this search is successful, then enquire whether the Work is still maintained.
228
229a. If it is being maintained, then ask the Current Maintainer to update their
230communication data within one month.
231
232b. If the search is unsuccessful or no action to resume active maintenance
233is taken by the Current Maintainer, then announce within the pertinent community
234your intention to take over maintenance. (If the Work is a LaTeX work, this
235could be done, for example, by posting to comp.text.tex.)
236
2373a. If the Current Maintainer is reachable and agrees to pass maintenance
238of the Work to you, then this takes effect immediately upon announcement.
239
240b. If the Current Maintainer is not reachable and the Copyright Holder agrees
241that maintenance of the Work be passed to you, then this takes effect immediately
242upon announcement.
243
2444. If you make an `intention announcement' as described in 2b. above and after
245three months your intention is challenged neither by the Current Maintainer
246nor by the Copyright Holder nor by other people, then you may arrange for
247the Work to be changed so as to name you as the (new) Current Maintainer.
248
2495. If the previously unreachable Current Maintainer becomes reachable once
250more within three months of a change completed under the terms of 3b) or 4),
251then that Current Maintainer must become or remain the Current Maintainer
252upon request provided they then update their communication data within one
253month.
254
255A change in the Current Maintainer does not, of itself, alter the fact that
256the Work is distributed under the LPPL license.
257
258If you become the Current Maintainer of the Work, you should immediately provide,
259within the Work, a prominent and unambiguous statement of your status as Current
260Maintainer. You should also announce your new status to the same pertinent
261community as in 2b) above.
262
263WHETHER AND HOW TO DISTRIBUTE WORKS UNDER THIS LICENSE
264
265======================================================
266
267This section contains important instructions, examples, and recommendations
268for authors who are considering distributing their works under this license.
269These authors are addressed as `you' in this section.
270
271Choosing This License or Another License
272
273----------------------------------------
274
275If for any part of your work you want or need to use *distribution* conditions
276that differ significantly from those in this license, then do not refer to
277this license anywhere in your work but, instead, distribute your work under
278a different license. You may use the text of this license as a model for your
279own license, but your license should not refer to the LPPL or otherwise give
280the impression that your work is distributed under the LPPL.
281
282The document `modguide.tex' in the base LaTeX distribution explains the motivation
283behind the conditions of this license. It explains, for example, why distributing
284LaTeX under the GNU General Public License (GPL) was considered inappropriate.
285Even if your work is unrelated to LaTeX, the discussion in `modguide.tex'
286may still be relevant, and authors intending to distribute their works under
287any license are encouraged to read it.
288
289A Recommendation on Modification Without Distribution
290
291-----------------------------------------------------
292
293It is wise never to modify a component of the Work, even for your own personal
294use, without also meeting the above conditions for distributing the modified
295component. While you might intend that such modifications will never be distributed,
296often this will happen by accident -- you may forget that you have modified
297that component; or it may not occur to you when allowing others to access
298the modified version that you are thus distributing it and violating the conditions
299of this license in ways that could have legal implications and, worse, cause
300problems for the community. It is therefore usually in your best interest
301to keep your copy of the Work identical with the public one. Many works provide
302ways to control the behavior of that work without altering any of its licensed
303components.
304
305How to Use This License
306
307-----------------------
308
309To use this license, place in each of the components of your work both an
310explicit copyright notice including your name and the year the work was authored
311and/or last substantially modified. Include also a statement that the distribution
312and/or modification of that component is constrained by the conditions in
313this license.
314
315Here is an example of such a notice and statement:
316
317%% pig.dtx
318
319%% Copyright 2005 M. Y. Name
320
321%
322
323% This work may be distributed and/or modified under the
324
325% conditions of the LaTeX Project Public License, either version 1.3
326
327% of this license or (at your option) any later version.
328
329% The latest version of this license is in
330
331% http://www.latex-project.org/lppl.txt
332
333% and version 1.3 or later is part of all distributions of LaTeX
334
335% version 2005/12/01 or later.
336
337%
338
339% This work has the LPPL maintenance status " maintained ".
340
341%
342
343% The Current Maintainer of this work is M. Y. Name .
344
345%
346
347% This work consists of the files pig.dtx and pig.ins
348
349% and the derived file pig.sty .
350
351Given such a notice and statement in a file, the conditions given in this
352license document would apply, with the `Work' referring to the three files
353`pig.dtx', `pig.ins', and `pig.sty' (the last being generated from `pig.dtx'
354using `pig.ins'), the `Base Interpreter' referring to any `LaTeX-Format',
355and both `Copyright Holder' and `Current Maintainer' referring to the person
356`M. Y. Name'.
357
358If you do not want the Maintenance section of LPPL to apply to your Work,
359change `maintained' above into `author-maintained'. However, we recommend
360that you use `maintained', as the Maintenance section was added in order to
361ensure that your Work remains useful to the community even when you can no
362longer maintain and support it yourself.
363
364Derived Works That Are Not Replacements
365
366---------------------------------------
367
368Several clauses of the LPPL specify means to provide reliability and stability
369for the user community. They therefore concern themselves with the case that
370a Derived Work is intended to be used as a (compatible or incompatible) replacement
371of the original Work. If this is not the case (e.g., if a few lines of code
372are reused for a completely different task), then clauses 6b and 6d shall
373not apply.
374
375Important Recommendations
376
377-------------------------
378
379Defining What Constitutes the Work
380
381The LPPL requires that distributions of the Work contain all the files of
382the Work. It is therefore important that you provide a way for the licensee
383to determine which files constitute the Work. This could, for example, be
384achieved by explicitly listing all the files of the Work near the copyright
385notice of each file or by using a line such as:
386
387% This work consists of all files listed in manifest.txt.
388
389in that place. In the absence of an unequivocal list it might be impossible
390for the licensee to determine what is considered by you to comprise the Work
391and, in such a case, the licensee would be entitled to make reasonable conjectures
392as to which files comprise the Work.
393