License

In December 1999, with the release of Zip 2.3, Info-ZIP switched from its old, ad hoc license (embodied in the COPYING file) to a new, more standard version based on the BSD license. Here is the text of the new license, which applies to all source files in Zip 2.3 and later, UnZip 5.41 and later, WiZ 5.0 and later, and MacZip 1.05 and later, except where explicitly stated otherwise:

This license is also available as plain ASCII:

• LICENSE (ASCII text)

The text in the LICENSE file should be identical to that above except for the absence of HTML markup (obviously). But in case of discrepancies in the actual wording, ftp://ftp.info-zip.org/pub/infozip/license.html is the definitive version.

Note that the lack of the BSD ``advertising clause'' and the presence of the third and fourth restrictions are the two principal differences from the BSD license. Restriction #3 is intended only to protect us from having to support other people's code and from getting blamed for other people's bugs. (We have enough bugs of our own. :-) )

Examples

Here are some examples of what we consider acceptable and unacceptable (i.e., misrepresentative) uses of the Info-ZIP names and contact info:

With regard to what defines a ``port'' (i.e., sufficiently different from ``our code'' that we would like you to be the first line of defense against bug reports), the usual rule of thumb is: if you didn't have to change any source code, it's not a new port. This includes cases where maybe you had to supply some unusual compiler flags (unless they have to do with aggressive optimizations that may fail unpredictably) or define a macro that isn't present in the standard makefile(s); we'd love to hear from you so that such things can be incorporated into future makefiles, but they don't constitute a port. The prototypical example is a new Unix variant, perhaps where it was necessary to compile via make -f unix/Makefile LOCAL_UNZIP="-DNO_UID_GID -DZMEM" all or something similar, but more typically where it wasn't necessary to do anything special.

Self-extracting Archives

As noted in condition #2, Info-ZIP's self-extractor stub, UnZipSFX, and its variants (such as SFXWiz) constitute a special case. Redistribution of those as part of a self-extracting archive, without the inclusion of the Info-ZIP license in accompanying documentation, is allowed as long as the normal SFX banner has not been removed or disabled. Note that the banner text may be extended, however. For example, it is completely acceptable (and desirable!) to append to the UnZipSFX banner a notice such as:

This archive is being distributed by XYZfoo Corporation. See http://www.XYZfooCorp.com/contacts/ for contact information and other help.

Exceptions

The license given above covers only Info-ZIP's code. There are five files in the Zip and UnZip distributions that are covered by separate copyrights and licenses:

• mktime.c (Zip)
• unreduce.c (UnZip)
• amiga/time_lib.c (Zip)
• macos/macstuff.c (Zip)
• macos/macstuff.h (Zip)

mktime.c is copyrighted by David MacKenzie and Michael Haertel and may be used freely as long as its copyright notice is retained and functional changes are noted. (In other words, its license is roughly equivalent to the Info-ZIP license.)

The full version of unreduce.c is the only remaining trace of Samuel H. Smith's original 1989 code, and its license explicitly prohibits commercial use and requires distribution of source code if the code is used in another program; as of UnZip 5.42, it is provided only as a separate add-on, not as part of the main UnZip distribution. (The stub version included with UnZip 5.42 and later is merely a placeholder and does not contain any of Smith's code.)

time_lib.c is copyrighted by Norbert Pueschel and may not be used commercially without the explicit permission of the copyright holder; non-commercial distribution by anyone other than Info-ZIP requires the inclusion of an additional piece of documentation.

macstuff.c and macstuff.h are derived from the More Files package and are copyrighted by Apple Computer and Jim Luther. They may be used without restriction provided that the source code is documented as having descended from Apple Sample Code and as containing subsequent changes. See the comments in the relevant source files for details.

In addition, versions of the following files that were released prior to this license were (and always will be) in the public domain. Newer versions are now covered by our copyright and license, but that doesn't affect the older copies:

• crypt.c (Zip and UnZip; both full version and dummy version)
• crypt.h (Zip and UnZip; both full version and dummy version)
• explode.c (UnZip)
• funzip.c (UnZip)
• inflate.c (UnZip)
• inflate.h (UnZip)
• os2/os2zip.c (Zip)
• os2/os2zip.h (Zip)

Finally, note that the copyright and license presented here do not give you any special rights with respect to patents, export regulations, trademarks, or other laws of the United States or other countries. This may or may not be an issue for the code in unshrink.c, crypt.c, crypt.h, etc.

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