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Info-ZIP's Zip
Initial releaseAugust 1992; 27 years ago (1992-08)
Stable release
3.00 / 7 July 2008; 11 years ago (2008-07-07)
Preview release
3.1d / 15 November 2015; 3 years ago (2015-11-15)
Written inC
TypeFile archiver
LicenseBSD-like license
Info-ZIP's UnZip
Original author(s)Samuel H. Smith[1]
Initial release3 March 1989; 30 years ago (1989-03-03)
Stable release
6.0 / 29 April 2009; 10 years ago (2009-04-29)
Preview release
6.10b / 10 December 2010; 8 years ago (2010-12-10)
Written inC
TypeFile archiver
LicenseBSD-like license
Developer(s)Mike White
Stable release
5.03 / 11 March 2005; 14 years ago (2005-03-11)
Written inC
Operating systemWindows 3.1 and later
PlatformIA-32, Alpha AXP (Windows NT series only)
TypeFile archiver
LicenseBSD-like license
Developer(s)Dirk Haase
Final release
1.06 / 22 February 2001; 18 years ago (2001-02-22)
Written inC
Operating systemMac OS Classic 7 or later
PlatformMotorola 68020 or later; PowerPC
TypeFile archiver
LicenseBSD-like license

Info-ZIP is a set of open-source software to handle ZIP archives. It has been in circulation since 1989. It consists of 4 separately-installable packages: the Zip and UnZip command-line utilities; and WiZ and MacZip, which are graphical user interfaces for archiving programs in Microsoft Windows and classic Mac OS, respectively.

Info-ZIP's Zip and UnZip have been ported to dozens of computing platforms. The UnZip web page describes UnZip as "The Third Most Portable Program in the World", surpassed by Hello World, C-Kermit, and possibly the Linux kernel.[2] The "zip" and "unzip" programs included with most Linux and Unix distributions are Info-ZIP's Zip and UnZip.

In addition to the Info-ZIP releases themselves, parts of Info-ZIP, including zlib, have been used in numerous other file archivers and other programs.[1] Many Info-ZIP programmers have also been involved in other projects closely related to the DEFLATE compression algorithm, such as the PNG image format and the zlib software library.[3]


The UnZip package also includes three additional utilities:

  • fUnZip extracts a file in a ZIP or gzip file directly to output from archives or other piped input.
  • UnZipSFX is software to make a ZIP file into an executable self-extracting archive.
  • ZipInfo outputs, in a variety of formats, information about ZIP files and their contents.

The Zip package includes three additional utilities:

  • ZipCloak adds or removes password encryption from file in a ZIP archive.
  • ZipNote allows the modification of comment fields in ZIP archives.
  • ZipSplit splits a ZIP archive into sections for separate disks or downloads.



UnZip 1.0 (March 1989) was released by Samuel M. Smith. It was written in Pascal and C. Pascal was abandoned soon after.

UnZip 2.0 (September 1989) was released by Samuel M. Smith. It included support for the "unimploding" (method 6) introduced by PKZIP 1.01. George Sipe created Unix version.

UnZip 2.0a (December 1989) was released by Carl Mascott and John Cowan.[3]

In Spring 1990, Info-ZIP was formed as a mailing list on SIMTEL20, and released

UnZip 3.0 (May 1990) became the first public release by Info-ZIP group.

UnZip 4.0 (December 1990) adds support of "central directory" within .ZIP archive.[3]

UnZip 5.0 (August 1992) introduces support of DEFLATE (method 8) compression method, used in PKZIP 1.93a.[3] Method 8 has become the de facto base standard for ZIP archives.

In 1994 and 1995 Info-ZIP turned a corner, and effectively became the de facto ZIP program on non-MS-DOS systems. A huge number of ports were released that year, including numerous minicomputers, mainframes and practically every microcomputer ever developed.[citation needed]

UnZip 5.41 (April 2000) was relicensed under Info-ZIP License.[3]

UnZip 5.50 (February 2002) adds support of Deflate64 (method 9) decompression.[4]

UnZip 6.0 adds support of "Zip64" .ZIP archive and bzip2 (method 12) decompression.[5] Support for bzip2-style compression was also in Zip from 3.0f beta.[6]


Zip 1.9 (August 1992) introduces support of DEFLATE (method 8) compression method.[3] Method 8 has become the de facto base standard for ZIP archives.

Zip 2.3 (December 1999) was the first Info-ZIP archiver tool under the new BSD-like Info-ZIP License.[3]

Zip 3.0 (2008-07-07) supports ZIP64 .ZIP archive, more than 65536 files per archive, multi-part archive, bzip2 compression, Unicode (UTF-8) filename and (partial) comment, Unix 32-bit UIDs/GIDs


WiZ 4.0 (November 1997) was released by Info-ZIP.[3]

WiZ 5.01 (April 2000) was relicensed under Info-ZIP License.[3]


MacZip 1.05 (July 2000) was released under Info-ZIP License.

MacZip 1.06 was released in February 2001. It was written by Dirk Hasse.[3]

See also[edit]


  1. ^ a b Roelofs, Greg (2008-07-08). "Info-ZIP Home Page". Retrieved 2010-11-16.
  2. ^ Roelofs, Greg (2009-09-10). "Info-ZIP's UnZip". Retrieved 2010-11-16.
  3. ^ a b c d e f g h i j Roelofs, Greg (2008-10-04). "Info-ZIP: More Stuff". Retrieved 2010-11-16.
  4. ^ Spieler, Christian (2002-02-17), "UnZip, version 5.5, 17 February 2002", UNZPHIST.ZIP, Info-ZIP
  5. ^ "README", Zip, 6.10a, Info-ZIP, 2010-08-13
  6. ^ "WHATSNEW", Zip, 3.1c, Info-ZIP, 2010-06-20

External links[edit]