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In computer science and information theory, data compression or source coding is the process of encoding information using fewer bits (or other information-bearing units) than an unencoded representation would use through use of specific encoding schemes. For example, this article could be encoded with fewer bits if we accept the convention that the word "compression" be encoded as "comp". One popular instance of compression that many computer users are familiar with is the ZIP file format, which, as well as providing compression, acts as an archiver, storing many files in a single output file.

As is the case with any form of communication, compressed data communication only works when both the sender and receiver of the information understand the encoding scheme. For example, this text makes sense only if the receiver understands that it is intended to be interpreted as characters representing the English language. Similarly, compressed data can only be understood if the decoding method is known by the receiver. Some compression algorithms exploit this property in order to encrypt data during the compression process so that decompression can only be achieved by an authorized party (eg. through the use of a password).

Compression is possible because most real-world data has statistical redundancy. For example, the letter 'e' is much more common in English text than the letter 'z', and the probability that the letter 'q' will be followed by the letter 'z' is rather small. Lossless compression algorithms usually exploit statistical redundancy in such a way as to represent the sender's data more concisely, but nevertheless perfectly.

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BigSpeed Zipper - Compact ZIP tool with unusual features such as browsing ZIP files before downloading and full-text search of ZIP file contents.
Meta Description: [ Secure File Sharing, Virtual Private Peer-to-Peer (P2P) Network, Instant Messaging, on-the-fly encryption, transparent compression, File Compression ActiveX Control, Data Compression Library, Zip Utility ]

Bzip2 and Libbzip2 - Patent free, high-quality data compressor for Windows or Unix.
Meta Description: [ Official Home Page for bzip2, the high-quality, open-source data compressor. The current stable version is bzip2 1.0.3. ]

Cathonian Ventures Ltd - Zipfusion - Flexible self-extractor, use with any zip tools that create type 0 (stored) and type 8 (deflate) format zip files. Feature a built-in configuration editor.
Meta Description: [ A powerful and versatile zip self-extractor ]

dczip - Freeware data compression utility for zip, tar, gzip and bzip2 files. Requires Java 1.3 or better.

404 Dzip - Compact Windows compression program that creates small .DZ archive files. Integrates with Windows Explorer.
Meta Description: [ Planet Quake is the epicenter for news on all Quake games, especially the upcoming Quake Wars. If you love the Quake 1, 2, 3, 4, or 5 engine - we have the latest reviews, guides and more ]

EnZip - Windows Explorer-integrated Zip program which can also build self-extracting archives with customized interfaces.

FileCompress Uharc Gui - A free Uharc 0.4 Gui with SFX and other features like preview of .uha file.
Meta Description: [ FileCompress.tk - A FREE Uharc GUI ]

Free WinZIP Alternatives - A roundup and review of fully WinZIP-compatible freeware ZIP programs -- compared on the basis of usability.
Meta Description: [ Free WinZIp Alternatives: A Roundup of Freeware Tools Suitable for Replacing WinZIP. ]

FreeZip - Windows zip utility that prides itself on being small, fast and efficient.
Meta Description: [ FreeZip - freeware zip and unzip software for MS Windows ]

Gzip - Open source command line data stream compressor and archiver.
Meta Description: [ The gzip home page: sources, executables, FAQ, ... ]

ICEOWS - Windows compression utility using the ARJ format (was called ArjFolder). Can extract, test, and view files stored in ZIP, GZIP, TAR, CAB, RAR, ACE, PK3, etc. and create SFX executables.
Meta Description: [ The official web site for ICEOWS.... ]

404 IZArc - This ZIP utility supports a huge number of compression formats including 7-ZIP. Also has AES encryption and a skinnable interface.

JustZIPit - Small and simple contextual menu based zip program with full ZIP-64 huge-archive compression.
Meta Description: [ Free-backup.info: Details about JustZIPit, a simple WinZIP alternative ]

LZX - Encoding for Amigas that uses large match offsets and file merging.
Meta Description: [ The information page about LZX, the most powerful archiver (freeware) available for Amiga. ]

MultiZipper - Unzip program for Windows that doesn't prompt before overwriting files. Supports shell links, drag and drop, and command line.

Quick Zip - Free zip compression utility for Windows, create, extract, and testing for zip archives.

StuffIt Expander - Decompresses all files in any of the StuffIt formats. It will also decode single and multi-part BinHex files. [Win/Solaris/Linux/Mac]
Meta Description: [ StuffIt is the easiest way to stuff and unstuff, zip, unzip, your files. Supports the most used formats on Windows (Zip and StuffIt/SIT), Macintosh (StuffIt/SIT), Unix (Tar/gzip) plus many more. ]

Tugzip - Free archiving utility with Windows integration, script support and ZIP-64 for huge archives. Website provides a free support forum.

UltimateZip - Supports a wide variety of archive types, creates self extracting archives, integrates with mail and virus scan, and integrates with Windows Explorer.
Meta Description: [ UltimateZip, the archiver for the future. ]

WinBZip2 - A small GUI utility for working with files in bzip2 format, compressing, decompressing and testing the integrity of bzip2 files.
Meta Description: [ WinBZip2 - Windows GUI utility for working with bzip2 files ]

WinGZip - A small GUI utility for working with files in gzip format. It allows to compress any file into gzip format, decompress and test the integrity of already gzipped files.
Meta Description: [ WinGZip - Windows GUI utility for working with gzip files ]

WinImp - Extracts ZIP, ARJ, RAR, TAR as well as higher-compression IMP format. Includes drag-and-drop capability and creation of custom SFX files which can launch a file after unpacking.

XStandard Zip Component - ZIP or unzip a file or folder using a single line of code with this free component. [ActiveX DLL]

Zip 2 Secure EXE - Utility to convert any ZIP file into a self-extracting executable. Supports AES encryption, can unpack automatically to a temporary directory and run a setup.exe after extraction.
Meta Description: [ ZIP 2 Secure EXE - Create Self-Extracting EXE (executables) from Zip Files, with AES encryption ]

zipdiff - An open source Java utility for comparing two zip files. Also suitable for JAR, EAR, WAR and RAR files.

Zipfocus - A small zip file reader for general use or restoring backups from floppy/flash/cd drive.
Meta Description: [ Small utility to read/extract zip files ]

ZipFree 2000 - ZIP tool with integrated virus check and integrated emailing for quick ZIP and send. Supports SFX creation and pre-extraction viewing.

ZIPGenius - A full-featured ZIP program with SFX and ZIP-64 support. Also supports AES encryption 7-ZIP format and integrated image-viewing.

ZipItFast - ZIP program with a skinned interface and full support for over 20 compression formats.

Zipper - Can zip, unzip and make executable files, and view unzip directories before software installation.
Meta Description: [ Free zip and unzip utility. Easy to use free zip program. Can zip, unzip and make executable files.View unzip directories before you install. High level of compression. ]

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