Zip Reads Biography & Facts
ZIP is an archive file format that supports lossless data compression. A ZIP file may contain one or more files or directories that may have been compressed. The ZIP file format permits a number of compression algorithms, though DEFLATE is the most common. This format was originally created in 1989 and was first implemented in PKWARE, Inc.'s PKZIP utility, as a replacement for the previous ARC compression format by Thom Henderson. The ZIP format was then quickly supported by many software utilities other than PKZIP. Microsoft has included built-in ZIP support (under the name "compressed folders") in versions of Microsoft Windows since 2000 (Windows Me). Apple has included built-in ZIP support in Mac OS X 10.3 (via BOMArchiveHelper, now Archive Utility) and later. Most free operating systems have built in support for ZIP in similar manners to Windows and Mac OS X.
ZIP files generally use the file extensions .zip or .ZIP and the MIME media type application/zip. ZIP is used as a base file format by many programs, usually under a different name. When navigating a file system via a user interface, graphical icons representing ZIP files often appear as a document or other object prominently featuring a zipper.
The .ZIP file format was designed by Phil Katz of PKWARE and Gary Conway of Infinity Design Concepts. The format was created after Systems Enhancement Associates (SEA) filed a lawsuit against PKWARE claiming that the latter's archiving products, named PKARC, were derivatives of SEA's ARC archiving system. The name "zip" (meaning "move at high speed") was suggested by Katz's friend, Robert Mahoney. They wanted to imply that their product would be faster than ARC and other compression formats of the time. The earliest known version of .ZIP File Format Specification was first published as part of PKZIP 0.9 package under the file APPNOTE.TXT in 1989. By distributing the zip file format within APPNOTE.TXT, compatibility with the zip file format proliferated widely on the public Internet during the 1990s.PKWARE and Infinity Design Concepts made a joint press release on February 14, 1989, releasing the .ZIP file format into the public domain.
The .ZIP File Format Specification has its own version number, which does not necessarily correspond to the version numbers for the PKZIP tool, especially with PKZIP 6 or later. At various times, PKWARE has added preliminary features that allow PKZIP products to extract archives using advanced features, but PKZIP products that create such archives are not made available until the next major release. Other companies or organizations support the PKWARE specifications at their own pace.
The .ZIP file format specification is formally named "APPNOTE - .ZIP File Format Specification" and it is published on the PKWARE.com website since the late 1990s. Several versions of the specification were not published. Specifications of some features such as BZIP2 compression, strong encryption specification and others were published by PKWARE a few years after their creation. The URL of the online specification was changed several times on the PKWARE website.
A summary of key advances in various versions of the PKWARE specification:
2.0: (1993) File entries can be compressed with DEFLATE and use traditional PKWARE encryption (ZipCrypto).
2.1: (1996) Deflate64 compression
4.5: (2001) Documented 64-bit zip format.
4.6: (2001) BZIP2 compression (not published online until the publication of APPNOTE 5.2)
5.0: (2002) SES: DES, Triple DES, RC2, RC4 supported for encryption (not published online until the publication of APPNOTE 5.2)
5.2: (2003) AES encryption support for SES (defined in APPNOTE 5.1 that was not published online) and AES from WinZip ("AE-x"); corrected version of RC2-64 supported for SES encryption.
6.1: (2004) Documented certificate storage.
6.2.0: (2004) Documented Central Directory Encryption.
6.3.0: (2006) Documented Unicode (UTF-8) filename storage. Expanded list of supported compression algorithms (LZMA, PPMd+), encryption algorithms (Blowfish, Twofish), and hashes.
6.3.1: (2007) Corrected standard hash values for SHA-256/384/512.
6.3.2: (2007) Documented compression method 97 (WavPack).
6.3.3: (2012) Document formatting changes to facilitate referencing the PKWARE Application Note from other standards using methods such as the JTC 1 Referencing Explanatory Report (RER) as directed by JTC 1/SC 34 N 1621.
6.3.4: (2014) Updates the PKWARE, Inc. office address.
6.3.5: (2018) Documented compression methods 16, 96 and 99, DOS timestamp epoch and precision, added extra fields for keys and decryption, as well as typos and clarifications.
6.3.6: (2019) Corrected typographical error.
6.3.7: (2020) Added Zstandard compression method ID 20.
6.3.8: (2020) Moved Zstandard compression method ID from 20 to 93, deprecating the former. Documented method IDs 94 and 95 (MP3 and XZ respectively).
6.3.9: (2020) Corrected a typo in Data Stream Alignment description.WinZip, starting with version 12.1, uses the extension .zipx for ZIP files that use compression methods newer than DEFLATE; specifically, methods BZip, LZMA, PPMd, Jpeg and Wavpack. The last 2 are applied to appropriate file types when "Best method" compression is selected.
In April 2010, ISO/IEC JTC 1 initiated a ballot to determine whether a project should be initiated to create an ISO/IEC International Standard format compatible with ZIP. The proposed project, entitled Document Packaging, envisaged a ZIP-compatible 'minimal compressed archive format' suitable for use with a number of existing standards including OpenDocument, Office Open XML and EPUB.
In 2015, ISO/IEC 21320-1 "Document Container File — Part 1: Core" was published which states that "Document container files are conforming Zip files". It requires the following main restrictions of the ZIP file format:
Files in ZIP archives may only be stored uncompressed, or using the "deflate" compression (i.e. compression method may contain the value "0" - stored or "8" - deflated).
The encryption features are prohibited.
The digital signature features (from SES) are prohibited.
The "patched data" features (from PKPatchMaker) are prohibited.
Archives may not span multiple volumes or be segmented.Design
.ZIP files are archives that store multiple files. ZIP allows contained files to be compressed using many different methods, as well as simply storing a file without compressing it. Each file is stored separately, allowing different files in the same archive to be compressed using different methods. Because the files in a ZIP archive are compressed individually, it is possible to extract them, or add new ones, without applying compression or decompression to the entire archive. This contrasts with the format of compressed tar files, for which such random-access processing is not easily possible.
A directory is placed at the end of a ZIP file. This identifies what files are in the ZIP and identif.... Discover the Zip Reads popular books. Find the top 100 most popular Zip Reads books.