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PKZip
PKZIP is a file archiving computer program, notable for introducing the popular ZIP file format. PKZIP was first introduced for MS-DOS 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 and marketed by his company PKWARE, Inc 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. 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 and others. Other archivers also appeared during the 1980s, including ARC by System Enhancement Associates, Inc. (SEA), Rahul Dhesi's ZOO, Dean W. Cooper's DWC, LHarc by Haruhiko ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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, military, healthcare and government. The company's products are intended to assist other companies in complying with various data protection regulations such as GDPR and CCPA. The company is headquartered in Milwaukee, Wisconsin with additional offices in the US, UK and India. PKWARE was founded in 1986 by Phil Katz, co-inventor of the ZIP standard. As of May 13, 2020, Thompson Street Capital Partners has acquired PKWARE Inc. History Compression software (1986–2000) PKWARE was founded in 1986 by Phil Katz, a software developer who had begun distributing a new file compression utility, called PKARC, as shareware. PKARC represented a radical improvement over existing compression software (including the ARC utility, on which it was based) and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zip (file Format)
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 1998 via the "Windows Plus!" addon for Windows 98. Native support was added as of the year 2000 in 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 ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 copyright lawsuit between System Enhancement Associates (SEA) and Katz's company, PKWARE, Inc., was widely publicized in the BBS community in the late 1980s. Phil Katz's software business was very successful, but he struggled with social isolation and chronic alcoholism in the last years of his life. Career Phil Katz was a graduate of Nicolet High School in Glendale, Wisconsin. Katz graduated from the Computer Science Engineering program at the University of Wisconsin–Milwaukee. After his graduation, he was hired by the Allen-Bradley company as a programmer. He wrote code to run programmable logic controllers, which operated manufacturing equipment on shop floors worldwide for Allen-Bradley's customers. PKARC and PKWARE Katz left Al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 otherwise specified in the footnotes section, comparisons are based on the stable versions—''without'' add-ons, extensions or external programs. Archivers ''Note: Archivers with names cell background highlighted in purple are no longer in development.'' General information Basic general information about the archivers. Notes: Operating system support The operating systems the archivers can run on without emulation or compatibility layer. Ubuntu's own GUI ''Archive manager,'' for example, can open and create many archive formats (including Rar archives) even to the extent of splitting into parts and encryption and ability to be read by the ''native program''. This is presumably a "compatibility layer." Notes: # A separate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 tar format uses the ASCII character encoding, current implementations use the UTF-8 (Unicode) encoding, which is backwards compatible with ASCII. Supports the external Parchive program (par2). From 3.20 release RAR can store modification, creation and last access time with the precision up to 0.0000001 second (= 0.1 µs) The PAQ family (with its lighter weight derivative LPAQ) went through many revisions, each revision suggested its own extension. For example: ".paq9a". WIM can store the ciphertext of encrypted files on an NTFS volume, but such files can only by decrypted if an administrator extracts the file to an NTFS volume, and the decryption key is available (typically from the file's original owner on the same Windows installation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bulletin Board System
A bulletin board system (BBS), also called computer bulletin board service (CBBS), is a computer server running software that allows users to connect to the system using a terminal program. Once logged in, the user can perform functions such as uploading and downloading software and data, reading news and bulletins, and exchanging messages with other users through public message boards and sometimes via direct chatting. In the early 1980s, message networks such as FidoNet were developed to provide services such as NetMail, which is similar to internet-based email. Many BBSes also offer online games in which users can compete with each other. BBSes with multiple phone lines often provide chat rooms, allowing users to interact with each other. Bulletin board systems were in many ways a precursor to the modern form of the World Wide Web, social networks, and other aspects of the Internet. Low-cost, high-performance asynchronous modems drove the use of online services and BBSes t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lempel–Ziv–Welch
Lempel–Ziv–Welch (LZW) is a universal lossless data compression algorithm created by Abraham Lempel, Jacob Ziv, and Terry Welch. It was published by Welch in 1984 as an improved implementation of the LZ78 algorithm published by Lempel and Ziv in 1978. The algorithm is simple to implement and has the potential for very high throughput in hardware implementations. It is the algorithm of the widely used Unix file compression utility compress and is used in the GIF image format. Algorithm The scenario described by Welch's 1984 paper encodes sequences of 8-bit data as fixed-length 12-bit codes. The codes from 0 to 255 represent 1-character sequences consisting of the corresponding 8-bit character, and the codes 256 through 4095 are created in a dictionary for sequences encountered in the data as it is encoded. At each stage in compression, input bytes are gathered into a sequence until the next character would make a sequence with no code yet in the dictionary. The co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ARC (file Format)
ARC is a lossless data compression and archival format by System Enhancement Associates (SEA). The file format and the program were both called ARC. The format is known as the subject of controversy in the 1980s, part of important debates over what would later be known as open formats. ARC was extremely popular during the early days of the dial-up BBS. ARC was convenient as it combined the functions of the SQ program to compress files and the LU program to create .LBR archives of multiple files. The format was later replaced by the ZIP format, which offered better compression ratios and the ability to retain directory structures through the compression/decompression process. The .arc filename extension is often used for several unrelated file archive-like file types. For example, the Internet Archive used its own ARC format to store multiple web resources into a single file. The FreeArc archiver also uses .arc extension, but uses a completely different file format. Nintendo u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Compression Software
In the pursuit of knowledge, data (; ) is a collection of discrete values that convey information, describing quantity, quality, fact, statistics, other basic units of meaning, or simply sequences of symbols that may be further interpreted. A datum is an individual value in a collection of data. Data is usually organized into structures such as tables that provide additional context and meaning, and which may themselves be used as data in larger structures. Data may be used as variables in a computational process. Data may represent abstract ideas or concrete measurements. Data is commonly used in scientific research, economics, and in virtually every other form of human organizational activity. Examples of data sets include price indices (such as consumer price index), unemployment rates, literacy rates, and census data. In this context, data represents the raw facts and figures which can be used in such a manner in order to capture the useful information out of it. Dat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Madison University
James Madison University (JMU, Madison, or James Madison) is a public research university in Harrisonburg, Virginia. Founded in 1908 as the State Normal and Industrial School for Women at Harrisonburg, the institution was renamed Madison College in 1938 in honor of President James Madison and then James Madison University in 1977. It is situated in the Shenandoah Valley, just west of Massanutten Mountain. History Founded in 1908 as a women's college, James Madison University was established by the Virginia General Assembly. It was originally called The State Normal and Industrial School for Women at Harrisonburg. In 1914, the name of the university was changed to the State Normal School for Women at Harrisonburg. At first, academic offerings included only today's equivalent of technical training or junior college courses, but authorization to award bachelor's degrees was granted in 1916. During this initial period of development, the campus plan was established and six bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 original code from the compressed code before executing it. In most cases this happens transparently so the compressed executable can be used in exactly the same way as the original. Executable compressors are often referred to as "runtime packers", "software packers", "software protectors" (or even " polymorphic packers" and " obfuscating tools"). A compressed executable can be considered a self-extracting archive, where a compressed executable is packaged along with the relevant decompression code in an executable file. Some compressed executables can be decompressed to reconstruct the original program file without being directly executed. Two programs that can be used to do this are CUP386 and UNP. Most compressed executables decompress the o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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, enterprise computing solutions, and business process solutions for organizations around the world. History Founding Unisys was formed in 1986 through the merger of mainframe corporations Sperry and Burroughs, with Burroughs buying Sperry for $4.8 billion. The name was chosen from over 31,000 submissions in an internal competition when Christian Machen submitted the word "Unisys" which was composed of parts of the words ''united'', ''information'' and ''systems''. The merger was the largest in the computer industry at the time and made Unisys the second largest computer company with annual revenue of $10.5 billion. Michael Blumenthal became CEO and Chairman. Soon after the merger, the market for proprietary mainframe-class systems—t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
