Zlib

infobox software
name = zlib

latest_release_version = 1.2.3
latest_release_date = 2005-07-18
programming language = C
operating_system = cross platform
genre = data compression
license = zlib license
website = [http://zlib.net/ zlib.net]

zlib is a software library used for data compression. zlib was written by Jean-loup Gailly and Mark Adler and is an abstraction of the DEFLATE compression algorithm used in their gzip file compression program. The first public version, 0.9, was released on 1 May 1995 and was originally intended for use with libpng image library. It is free software, distributed under the zlib license.

As of March 2007, zlib is included in Coverity’s Department of Homeland Security-sponsored ongoing examination of select open-source projects. [citation|title = Press release: Critical Open Source Software Projects Receive 6,000 Bug Fixes in First Year of Coverity Scan Site|url = http://www.coverity.com/html/press_story35_03_27_07.html|date = 2007-03-27|accessdate = 2007-12-10|publisher = Coverity.]

Applications

Today, zlib is something of a "de facto" standard, to the point that zlib and DEFLATE are often used interchangeably in standards documents. Thousands of applications rely on it for compression, directly or indirectly, [citation|title = zlib Applications|url = http://zlib.net/apps.html|date = 2002-04-18|first1 = Jean-loup|last1 = Gailly|first2 = Mark|last2 = Adler.] including:
* The Linux kernel, where it is used to implement compressed network protocols, compressed file systems and to decompress the kernel image itself at boot time.
* libpng, the reference implementation for the PNG image format, which specifies DEFLATE as the stream compression for its bitmap data.
* The Apache HTTP server, which uses zlib to implement HTTP/1.1.
* The OpenSSH client and server, which rely on zlib to perform the optional compression offered by the Secure Shell protocol.
* The OpenSSL and GnuTLS security libraries, which can optionally use zlib to compress TLS connections.
* The FFmpeg multimedia library, which uses zlib to read and write the DEFLATE-compressed parts of stream formats such as Matroska.
* The rsync remote file synchronizer, which uses zlib to implement optional protocol compression.
* The dpkg and RPM package managers, which use zlib to unpack files from compressed software packages.
* The Subversion and CVS version control systems, which use zlib to compress traffic to and from remote repositories.

zlib is also used in many embedded devices because the code is portable, liberally-licensed and has a relatively small memory footprint.

See also

* ZIP (file format)
* RFC 1950, RFC 1951, RFC 1952

References

External links

* [http://zlib.net zlib home page]