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Info-Zip License 1997-10
Info-Zip License 1997-10
  • Copyright (c) 1992 Igor Mandrichenko
  • Copyright (c) 1994 Greg Roelofs
  • Copyright (c) 1996 Mike White
  • Copyright 1989 Samuel H. Smith
  • copyrighted 1997 by Steve P. Miller
  • copyrighted by Norbert Pueschel, <>
  • Greg Roelofs
  • Igor Mandrichenko
  • Mike White
  • Norbert Pueschel
  • Samuel H. Smith
  • Steve P. Miller
  • many people associated with the Info-ZIP group
  • the Info-ZIP group
This is the Info-ZIP file COPYING (for UnZip), last updated 5 Oct 97.

There are currently six explicit copyrights on portions of UnZip
code (at least, of which Info-ZIP is aware):  the original Sam Smith
copyright on unzip 2.0, upon which Info-ZIP's UnZip 3.0 was based;
Igor Mandrichenko's copyright on his routines in vms.c; Greg Roelofs'
copyright on zipinfo.c and the new version of unshrink.c; Mike White's
copyright on the Windows DLL code (windll/*); Steve P. Miller's
copyright on the Pocket UnZip GUI (wince/*); and Norbert Pueschel's
copyright on the Amiga time.lib code.  In addition, Mark Adler has
placed inflate.h, inflate.c, explode.c and funzip.c into the public
domain; i.e., these files may be used without any restrictions beyond
those of simple courtesy (credit where it's due).  All of these are
discussed immediately below.  The remaining code is covered by an im-
plicit copyright under US law.  Frequently Asked Questions regarding
(re)distribution of Zip and UnZip are near the end of this file.

There are no known patents on any of the code in UnZip.  Unisys
claims a patent on LZW encoding and on LZW decoding _in an apparatus
that performs LZW encoding_, but the patent appears to exempt a stand-
alone decoder (as in UnZip's unshrink.c).  Unisys has publicly claimed
otherwise, but the issue has never been tested in court.  Since this
point is unclear, unshrinking is not enabled by default.  It is the
responsibility of the user to make his or her peace with Unisys and
its licensing requirements.  (unshrink.c may be removed from future
releases altogether.)

The original unzip source code has been extensively modified and
almost entirely rewritten (changes include random zipfile access
rather than sequential; replacement of unimplode() with explode();
replacement of old unshrink() with new (unrelated) unshrink(); re-
placement of output routines; addition of inflate(), wildcards,
filename-mapping, text translation, ...; etc.).  As far as we can
tell, the only remaining code that is substantially similar to
Mr. Smith's is that in the file unreduce.c, which now by default
is NOT compiled.  The following copyright applies to unreduce.c:

  * Copyright 1989 Samuel H. Smith;  All rights reserved
  * Do not distribute modified versions without my permission.
  * Do not remove or alter this notice or any other copyright notice.
  * If you use this in your own program you must distribute source code.
  * Do not use any of this in a commercial product.

Regarding the first stipulation, Mr. Smith was tracked down in southern
California some years back [Samuel H. Smith, The Tool Shop; as of mid-
May 1994, (213) 851-9969 (voice), (213) 887-2127(?) (subscription BBS),]:

"He says that he thought that whoever contacted him understood that
 he has no objection to the Info-ZIP group's inclusion of his code.
 His primary concern is that it remain freely distributable, he said."

Despite the fact that our "normal" code has been entirely rewritten
and by default no longer contains any of Mr. Smith's code, Info-ZIP
remains indebted and grateful to him.  We hope he finds our contribu-
tions as useful as we have his.

Note that the third and fourth stipulations still apply to any com-
pany that wishes to incorporate the unreduce code into its products;
if you wish to do so, you must contact Mr. Smith directly regarding

The following copyright applies to most of the VMS code in vms.c,
distributed with UnZip version 4.2 and later:

  * Copyright (c) 1992 Igor Mandrichenko.
  * Permission is granted to any individual or institution to use,
  * copy, or redistribute this software so long as all of the orig-
  * inal files are included unmodified, that it is not sold for
  * profit, and that this copyright notice is retained.

The following copyright applies to the new version of unshrink.c,
distributed with UnZip version 5.2 and later:

  * Copyright (c) 1994 Greg Roelofs.
  * Permission is granted to any individual/institution/corporate
  * entity to use, copy, redistribute or modify this software for
  * any purpose whatsoever, subject to the conditions noted in the
  * Frequently Asked Questions section below, plus one additional
  * condition:  namely, that my name not be removed from the source
  * code.  (Other names may, of course, be added as modifications
  * are made.)  Corporate legal staff (like at IBM :-) ) who have
  * problems understanding this can contact me through Zip-Bugs...

The following copyright applies to the Windows DLL code (windll/*),
distributed with UnZip version 5.2 and later:

  * Copyright (c) 1996 Mike White.
  * Permission is granted to any individual or institution to use,
  * copy, or redistribute this software so long as all of the original
  * files are included, that it is not sold for profit, and that this
  * copyright notice is retained.

The following copyright applies to the Windows CE GUI port, ``Pocket
UnZip,'' distributed with UnZip version 5.3 and later:

  * All the source files for Pocket UnZip, except for components
  * written by the Info-ZIP group, are copyrighted 1997 by Steve P.
  * Miller.  The product "Pocket UnZip" itself is property of the
  * author and cannot be altered in any way without written consent
  * from Steve P. Miller.

The following copyright applies to the Amiga time code (amiga/time_lib.c),
distributed with UnZip version 5.32 and later:

  * This source is copyrighted by Norbert Pueschel,
  *   <>.
  * From 'clockdaemon.readme' (available from Aminet, including
  * "The original SAS/C functions gmtime, localtime, mktime and time
  * do not work correctly. The supplied link library time.lib contains
  * replacement functions for them."
  * Permission is granted to the Info-ZIP group to redistribute the
  * time.lib source.  The use of time.lib functions in own, noncommerical
  * programs is permitted.  It is only required to add the timezone.doc
  * to such a distribution.  Using the time.lib library in commerical
  * software (including shareware) is only permitted after prior
  * consultation of the author.

The remaining code was written by many people associated with the
Info-ZIP group, with large contributions from (but not limited to):
Greg Roelofs (overall program logic, ZipInfo, unshrink, filename
mapping/portability, etc.), Mark Adler (inflate, explode, funzip),
Kai Uwe Rommel (OS/2), John Bush and Paul Kienitz (Amiga), Antoine
Verheijen (Macintosh), Hunter Goatley (more VMS), Mike White (Windows
DLLs), Christian Spieler (overall logic, optimization, VMS, etc.) and
others.  See the file CONTRIBS in the source distribution for a much
more complete list of contributors.  As noted above, Mark Adler's
inflate.[ch], explode.c and funzip.c are in the public domain, and
everything that isn't otherwise accounted for is implicitly copy-
righted by Info-ZIP.  In other words, use it with our blessings, but
it's still our code.  Thank you!


Frequently Asked Questions about distributing Zip and UnZip:

Q. Can I distribute Zip and UnZip sources and/or executables?

A. You may redistribute the latest official distributions without
   any modification, and without even asking us for permission.
   (Note that an "executable distribution" includes documentation,
   even if it's in a separate zipfile; plain executables do NOT
   count.)  You can charge for the cost of the media (CDROM, disk-
   ettes, etc.), the compilation (e.g., of a software archive),
   and a small copying fee.  Distributed archives should follow
   the naming conventions used in the `WHERE' file.  If you want
   to distribute modified versions, please contact us at first.  You must not distribute beta
   versions without explicit permission to do so.

Q. Can I use the executables (or DLLs) of Zip and UnZip to distribute
   my software?

A. Yes, so long as it is clear that Zip and UnZip are not being
   sold, that the source code is freely available, and that there
   are no extra or hidden charges resulting from its use by or in-
   clusion with the commercial product.  Here is an example of a
   suitable notice:

      NOTE:  <Product> is packaged on this CD using Info-ZIP's
      compression utility.  The installation program uses UnZip
      to read zip files from the CD.  Info-ZIP's software (Zip,
      UnZip and related utilities) is free and can be obtained
      as source code or executables from Internet/WWW sites,
      including .

   If the distribution is being done with UnZipSFX instead of a DLL
   or stand-alone copy of UnZip (i.e., as one or more self-extracting
   archives), no notice is required as long as the normal UnZipSFX
   banner has not been removed.

Q. Can I use the source code of Zip and UnZip in my commercial

A. Yes, so long as you include in your product an acknowledgment; a
   pointer to the original, free compression sources; and a statement
   making it clear that there are no extra or hidden charges resulting
   from the use of our compression code in your product (see below for
   an example).  The acknowledgment should appear in at least one piece 
   of human-readable documentation (e.g., a README file or man page),
   although additionally putting it in the executable(s) is OK, too.
   In other words, you are allowed to sell only your own work, not ours,
   and we'd like a little credit.  (Note the additional restrictions
   above on the code in unreduce.c, unshrink.c, vms.c, time_lib.c, and
   everything in the wince and windll subdirectories.)  Contact us at if you have special requirements.  We also
   like to hear when our code is being used, but we don't require that.

      <Product> incorporates compression code from the Info-ZIP group.
      There are no extra charges or costs due to the use of this code,
      and the original compression sources are freely available from or
      on the Internet.

   If you only need compression capability, not full zipfile support,
   you might want to look at zlib instead; it has fewer restrictions
   on commercial use.  See .