PKZIP is a
file archiving computer program
A computer program is a sequence or set of instructions in a programming language for a computer to execute. Computer programs are one component of software, which also includes documentation and other intangible components.
A computer program ...
, notable for introducing the popular
ZIP file format. PKZIP was first introduced for
MS-DOS
MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few ope ...
on the
IBM-PC compatible platform in 1989. Since then versions have been released for a number of other architectures and operating systems. PKZIP was originally written by
Phil Katz
Phillip Walter Katz (November 3, 1962 – April 14, 2000) was a computer programmer best known as the co-creator of the Zip file format for data compression, and the author of PKZIP, a program for creating zip files that ran under DOS. A ...
and marketed by his company
PKWARE, Inc
PKWARE, Inc. is an enterprise data protection software company that provides discovery, classification, masking and encryption solutions, along with data compression software, used by organizations in financial services, manufacturing, militar ...
starting in 1986. The company bears his initials: 'PK'.
History
By the 1970s, file archiving programs were distributed as standard utilities with operating systems. They include the
Unix utilities ar, shar, and
tar
Tar is a dark brown or black viscous liquid of hydrocarbons and free carbon, obtained from a wide variety of organic materials through destructive distillation. Tar can be produced from coal, wood, petroleum, or peat. "a dark brown or black bit ...
. These utilities were designed to gather a number of separate files into a single archive file for easier copying and distribution. These archives could optionally be passed through a stream compressor utility, such as
compress
compress is a Unix shell compression program based on the LZW compression algorithm. Compared to more modern compression utilities such as gzip and bzip2, compress performs faster and with less memory usage, at the cost of a significantly l ...
and others.
Other archivers also appeared during the 1980s, including
ARC by System Enhancement Associates, Inc. (SEA), Rahul Dhesi's
ZOO
A zoo (short for zoological garden; also called an animal park or menagerie) is a facility in which animals are kept within enclosures for public exhibition and often bred for conservation purposes.
The term ''zoological garden'' refers to zoo ...
, Dean W. Cooper's DWC,
LHarc
LHA or LZH is a freeware compression utility and associated file format. It was created in 1988 by , a doctor and originally named LHarc. A complete rewrite of LHarc, tentatively named ''LHx'', was eventually released as ''LH''. It was then rena ...
by Haruhiko Okomura and Haruyasu Yoshizaki and
ARJ
ARJ (Archived by Robert Jung) is a software tool designed by Robert K. Jung for creating high-efficiency data compression, compressed file archives. ARJ is currently on version 2.86 for MS-DOS and 3.20 for Microsoft Windows and supports 16-bit, 3 ...
which stands for "Archived by Robert Jung".
The development of PKZIP was first announced in the file SOFTDEV.DOC from within the PKPAK 3.61 package, stating it would develop a new and yet unnamed compression program. The announcement had been made following the lawsuit between SEA and PKWARE, Inc. Although SEA won the suit, it lost the compression war, as the user base migrated to PKZIP as the compressor of choice. Led by some
BBS
BBS may refer to:
Ammunition
* BBs, BB gun metal bullets
* BBs, airsoft gun plastic pellets
Computing and gaming
* Bulletin board system, a computer server users dial into via dial-up or telnet; precursor to the Internet
* BIOS Boot Specificat ...
sysop
A sysop (; an abbreviation of system operator) is an administrator of a multi-user computer system, such as a bulletin board system (BBS) or an online service virtual community.Jansen, E. & James,V. (2002). NetLingo: the Internet dictionary. Netl ...
s who refused to accept or offer files compressed as .ARC files, users began recompressing any old archives that were currently stored in .ARC format into .ZIP files.
The first version was released in 1989, as a
DOS
DOS is shorthand for the MS-DOS and IBM PC DOS family of operating systems.
DOS may also refer to:
Computing
* Data over signalling (DoS), multiplexing data onto a signalling channel
* Denial-of-service attack (DoS), an attack on a communicat ...
command-line tool, distributed under
shareware
Shareware is a type of proprietary software that is initially shared by the owner for trial use at little or no cost. Often the software has limited functionality or incomplete documentation until the user sends payment to the software developer ...
model with a US$25 registration fee (US$47 with manual).
.ZIP file format
To help ensure the interoperability of the ZIP format, Phil Katz published the original .ZIP File Format Specification in the APPNOTE.TXT documentation file. PKWARE continued to maintain this document and periodically published updates.
Originally only bundled with registered versions of PKZIP, it was later available on the PKWARE site.
The specification has its own version number, which does not necessarily correspond to the PKZIP version numbers, especially with PKZIP 6 or later. At various times, PKWARE adds preliminary features that allows PKZIP products to extract archives using advanced features, but PKZIP products that create such archives won't be available until the next major release.
Compatibility
Although popular at the time, ZIP archives using PKZIP 1.0 compression methods are now rare, and many unzip tools such as
7-Zip
7-Zip is a free and open-source file archiver, a utility used to place groups of files within compressed containers known as "archives". It is developed by Igor Pavlov and was first released in 1999. 7-Zip has its own archive format called 7z, ...
are able to read and write several other archive formats.
Patents
Shrinking uses dynamic
LZW, on which
Unisys
Unisys Corporation is an American multinational information technology (IT) services and consulting company headquartered in Blue Bell, Pennsylvania. It provides digital workplace solutions, cloud, applications, and infrastructure solutions, e ...
held patents. A patent for the Reduce Algorithm had also been filed on June 19, 1984, long before PKZIP was produced.
See also
*
Comparison of file archivers
The following tables compare general and technical information for a number of file archivers. Please see the individual products' articles for further information. They are neither all-inclusive nor are some entries necessarily up to date. Unless ...
*
List of archive formats
This is a list of file formats used by archivers and compressors used to create archive files.
Archiving only
Compression only
Archiving and compression
Data recovery
Comparison Containers and compression
Notes
While the original ...
*
PKLite
Executable compression is any means of compressing an executable file and combining the compressed data with decompression code into a single executable. When this compressed executable is executed, the decompression code recreates the origina ...
References
External links
Official
* , PKWARE
PKZIP from PKWARE
PKZIP 2.50 for DOSSecureZIP from PKWARE
APPNOTE
Other
SecureZIP Homepage*
ttp://www.bbsdocumentary.com/library/CONTROVERSY/LAWSUITS/SEA/ CONTROVERSY: LAWSUITS: SEA vs. PKWARE*
Judgment in favor of SEA in ''SEA v. PKWARE and Phil Katz''
{{DEFAULTSORT:Pkzip
Data compression software
File archivers
Windows compression software