Wikipedia is a multilingual online encyclopedia with free content and no ads, based on open collaboration through a model of content edit by web-based applications like web browsers, called wiki. It is the largest and most popular general reference work on the World Wide Web, is one of the most popular websites by Alexa rank as of April 2019, it is owned and supported by the Wikimedia Foundation, a non-profit organization that operates on money it receives from donors to remain ad free. Wikipedia was launched on January 2001, by Jimmy Wales and Larry Sanger. Sanger coined its name, as a portmanteau of wiki and "encyclopedia". An English-language encyclopedia, versions in other languages were developed. With 5,838,942 articles, the English Wikipedia is the largest of the more than 290 Wikipedia encyclopedias. Overall, Wikipedia comprises more than 40 million articles in 301 different languages and by February 2014 it had reached 18 billion page views and nearly 500 million unique visitors per month.
In 2005, Nature published a peer review comparing 42 hard science articles from Encyclopædia Britannica and Wikipedia and found that Wikipedia's level of accuracy approached that of Britannica, although critics suggested that it might not have fared so well in a similar study of a random sampling of all articles or one focused on social science or contentious social issues. The following year, Time magazine stated that the open-door policy of allowing anyone to edit had made Wikipedia the biggest and the best encyclopedia in the world, was a testament to the vision of Jimmy Wales. Wikipedia has been criticized for exhibiting systemic bias, for presenting a mixture of "truths, half truths, some falsehoods", for being subject to manipulation and spin in controversial topics. In 2017, Facebook announced that it would help readers detect fake news by suitable links to Wikipedia articles. YouTube announced a similar plan in 2018. Other collaborative online encyclopedias were attempted before Wikipedia, but none were as successful.
Wikipedia began as a complementary project for Nupedia, a free online English-language encyclopedia project whose articles were written by experts and reviewed under a formal process. It was founded on March 2000, under the ownership of Bomis, a web portal company, its main figures were Bomis CEO Jimmy Wales and Larry Sanger, editor-in-chief for Nupedia and Wikipedia. Nupedia was licensed under its own Nupedia Open Content License, but before Wikipedia was founded, Nupedia switched to the GNU Free Documentation License at the urging of Richard Stallman. Wales is credited with defining the goal of making a publicly editable encyclopedia, while Sanger is credited with the strategy of using a wiki to reach that goal. On January 10, 2001, Sanger proposed on the Nupedia mailing list to create a wiki as a "feeder" project for Nupedia; the domains wikipedia.com and wikipedia.org were registered on January 12, 2001 and January 13, 2001 and Wikipedia was launched on January 15, 2001, as a single English-language edition at www.wikipedia.com, announced by Sanger on the Nupedia mailing list.
Wikipedia's policy of "neutral point-of-view" was codified in its first months. Otherwise, there were few rules and Wikipedia operated independently of Nupedia. Bomis intended to make Wikipedia a business for profit. Wikipedia gained early contributors from Nupedia, Slashdot postings, web search engine indexing. Language editions were created, with a total of 161 by the end of 2004. Nupedia and Wikipedia coexisted until the former's servers were taken down permanently in 2003, its text was incorporated into Wikipedia; the English Wikipedia passed the mark of two million articles on September 9, 2007, making it the largest encyclopedia assembled, surpassing the 1408 Yongle Encyclopedia, which had held the record for 600 years. Citing fears of commercial advertising and lack of control in Wikipedia, users of the Spanish Wikipedia forked from Wikipedia to create the Enciclopedia Libre in February 2002; these moves encouraged Wales to announce that Wikipedia would not display advertisements, to change Wikipedia's domain from wikipedia.com to wikipedia.org.
Though the English Wikipedia reached three million articles in August 2009, the growth of the edition, in terms of the numbers of new articles and of contributors, appears to have peaked around early 2007. Around 1,800 articles were added daily to the encyclopedia in 2006. A team at the Palo Alto Research Center attributed this slowing of growth to the project's increasing exclusivity and resistance to change. Others suggest that the growth is flattening because articles that could be called "low-hanging fruit"—topics that merit an article—have been created and built up extensively. In November 2009, a researcher at the Rey Juan Carlos University in Madrid found that the English Wikipedia had lost 49,000 editors during the first three months of 2009; the Wall Street Journal cited the array of rules applied to editing and disputes related to such content among the reasons for this trend. Wales disputed these claims in 2009, denying the decline and questioning the methodology of the study. Two years in 2011, Wales acknowledged the presence of a slight decline, noting a decrease from "a little more than 36,000 writers" in June 2010 to 35,800 in June 2011.
In the same interview, Wales claimed the number of editors was "stable and sustainable". A 2013 article titled; the article revealed
RSS is a type of web feed which allows users and applications to access updates to online content in a standardized, computer-readable format. These feeds can, for example, allow a user to keep track of many different websites in a single news aggregator; the news aggregator will automatically check the RSS feed for new content, allowing the content to be automatically passed from website to website or from website to user. This passing of content is called web syndication. Websites use RSS feeds to publish updated information, such as blog entries, news headlines, or episodes of audio and video series. RSS is used to distribute podcasts. An RSS document includes full or summarized text, metadata, like publishing date and author's name. A standard XML file format ensures compatibility with many different machines/programs. RSS feeds benefit users who want to receive timely updates from favourite websites or to aggregate data from many sites. Subscribing to a website RSS removes the need for the user to manually check the website for new content.
Instead, their browser monitors the site and informs the user of any updates. The browser can be commanded to automatically download the new data for the user. RSS feed data is presented to users using software called a news aggregator; this aggregator can be built into a website, installed on a desktop computer, or installed on a mobile device. Users subscribe to feeds either by entering a feed's URI into the reader or by clicking on the browser's feed icon; the RSS reader checks the user's feeds for new information and can automatically download it, if that function is enabled. The reader provides a user interface; the RSS formats were preceded by several attempts at web syndication that did not achieve widespread popularity. The basic idea of restructuring information about websites goes back to as early as 1995, when Ramanathan V. Guha and others in Apple Computer's Advanced Technology Group developed the Meta Content Framework. RDF Site Summary, the first version of RSS, was created by Dan Libby and Ramanathan V. Guha at Netscape.
It was released in March 1999 for use on the My. Netscape. Com portal; this version became known as RSS 0.9. In July 1999, Dan Libby of Netscape produced a new version, RSS 0.91, which simplified the format by removing RDF elements and incorporating elements from Dave Winer's news syndication format. Libby renamed the format from RDF to RSS Rich Site Summary and outlined further development of the format in a "futures document"; this would be Netscape's last participation in RSS development for eight years. As RSS was being embraced by web publishers who wanted their feeds to be used on My. Netscape. Com and other early RSS portals, Netscape dropped RSS support from My. Netscape. Com in April 2001 during new owner AOL's restructuring of the company removing documentation and tools that supported the format. Two parties emerged to fill the void, with neither Netscape's help nor approval: The RSS-DEV Working Group and Dave Winer, whose UserLand Software had published some of the first publishing tools outside Netscape that could read and write RSS.
Winer published a modified version of the RSS 0.91 specification on the UserLand website, covering how it was being used in his company's products, claimed copyright to the document. A few months UserLand filed a U. S. trademark registration for RSS, but failed to respond to a USPTO trademark examiner's request and the request was rejected in December 2001. The RSS-DEV Working Group, a project whose members included Guha and representatives of O'Reilly Media and Moreover, produced RSS 1.0 in December 2000. This new version, which reclaimed the name RDF Site Summary from RSS 0.9, reintroduced support for RDF and added XML namespaces support, adopting elements from standard metadata vocabularies such as Dublin Core. In December 2000, Winer released RSS 0.92 a minor set of changes aside from the introduction of the enclosure element, which permitted audio files to be carried in RSS feeds and helped spark podcasting. He released drafts of RSS 0.93 and RSS 0.94 that were subsequently withdrawn. In September 2002, Winer released a major new version of the format, RSS 2.0, that redubbed its initials Really Simple Syndication.
RSS 2.0 removed the type attribute added support for namespaces. To preserve backward compatibility with RSS 0.92, namespace support applies only to other content included within an RSS 2.0 feed, not the RSS 2.0 elements themselves. Because neither Winer nor the RSS-DEV Working Group had Netscape's involvement, they could not make an official claim on the RSS name or format; this has fueled ongoing controversy in the syndication development community as to which entity was the proper publisher of RSS. One product of that contentious debate was the creation of an alternative syndication format, that began in June 2003; the Atom syndication format, whose creation was in part motivated by a desire to get a clean start free of the issues surrounding RSS, has been adopted as IETF Proposed Standard RFC 4287. In July 2003, Winer and UserLand Software assigned the copyright of the RSS 2.0 specification to Harvard's Berkman Center for Internet & Society, where he had just begun a term as a visiting fellow.
At the same time, Winer launched the RSS Advisory Board with Brent Simmons and Jon Udell, a group whose purpose was to maintain and publ
A film called a movie, motion picture, moving picture, or photoplay, is a series of still images that, when shown on a screen, create the illusion of moving images. This optical illusion causes the audience to perceive continuous motion between separate objects viewed in rapid succession; the process of filmmaking is both an industry. A film is created by photographing actual scenes with a motion-picture camera, by photographing drawings or miniature models using traditional animation techniques, by means of CGI and computer animation, or by a combination of some or all of these techniques, other visual effects; the word "cinema", short for cinematography, is used to refer to filmmaking and the film industry, to the art of filmmaking itself. The contemporary definition of cinema is the art of simulating experiences to communicate ideas, perceptions, beauty or atmosphere by the means of recorded or programmed moving images along with other sensory stimulations. Films were recorded onto plastic film through a photochemical process and shown through a movie projector onto a large screen.
Contemporary films are now fully digital through the entire process of production and exhibition, while films recorded in a photochemical form traditionally included an analogous optical soundtrack. Films are cultural artifacts created by specific cultures, they reflect those cultures. Film is considered to be an important art form, a source of popular entertainment, a powerful medium for educating—or indoctrinating—citizens; the visual basis of film gives it a universal power of communication. Some films have become popular worldwide attractions through the use of dubbing or subtitles to translate the dialog into other languages; the individual images that make up a film are called frames. In the projection of traditional celluloid films, a rotating shutter causes intervals of darkness as each frame, in turn, is moved into position to be projected, but the viewer does not notice the interruptions because of an effect known as persistence of vision, whereby the eye retains a visual image for a fraction of a second after its source disappears.
The perception of motion is due to a psychological effect called the phi phenomenon. The name "film" originates from the fact that photographic film has been the medium for recording and displaying motion pictures. Many other terms exist for an individual motion-picture, including picture, picture show, moving picture and flick; the most common term in the United States is movie. Common terms for the field in general include the big screen, the silver screen, the movies, cinema. In early years, the word sheet was sometimes used instead of screen. Preceding film in origin by thousands of years, early plays and dances had elements common to film: scripts, costumes, direction, audiences and scores. Much terminology used in film theory and criticism apply, such as mise en scène. Owing to the lack of any technology for doing so, the moving images and sounds could not be recorded for replaying as with film; the magic lantern created by Christiaan Huygens in the 1650s, could be used to project animation, achieved by various types of mechanical slides.
Two glass slides, one with the stationary part of the picture and the other with the part, to move, would be placed one on top of the other and projected together the moving slide would be hand-operated, either directly or by means of a lever or other mechanism. Chromotrope slides, which produced eye-dazzling displays of continuously cycling abstract geometrical patterns and colors, were operated by means of a small crank and pulley wheel that rotated a glass disc. In the mid-19th century, inventions such as Joseph Plateau's phenakistoscope and the zoetrope demonstrated that a designed sequence of drawings, showing phases of the changing appearance of objects in motion, would appear to show the objects moving if they were displayed one after the other at a sufficiently rapid rate; these devices relied on the phenomenon of persistence of vision to make the display appear continuous though the observer's view was blocked as each drawing rotated into the location where its predecessor had just been glimpsed.
Each sequence was limited to a small number of drawings twelve, so it could only show endlessly repeating cyclical motions. By the late 1880s, the last major device of this type, the praxinoscope, had been elaborated into a form that employed a long coiled band containing hundreds of images painted on glass and used the elements of a magic lantern to project them onto a screen; the use of sequences of photographs in such devices was limited to a few experiments with subjects photographed in a series of poses because the available emulsions were not sensitive enough to allow the short exposures needed to photograph subjects that were moving. The sensitivity was improved and in the late 1870s, Eadweard Muybridge created the first animated image sequences photographed in real-time. A row of cameras was used, each, in turn, capturing one image on a photographic glass plate, so the total number of images in each sequence was limited by the number of cameras, about two dozen at most. Muybridge used his system to analyze the movements of a wi
Slashdot is a social news website that billed itself as "News for Nerds. Stuff that Matters", it features news stories on science and politics that are submitted and evaluated by site users and editors. Each story has a comments section attached to it; the website was founded in 1997 by Hope College students Rob Malda known as "CmdrTaco", classmate Jeff Bates known as "Hemos". In 2012, they sold it to DHI Group, Inc.. In January 2016, BizX acquired Slashdot Media, including SourceForge. Summaries of stories and links to news articles are submitted by Slashdot's own users, each story becomes the topic of a threaded discussion among users. Discussion is moderated by a user-based moderation system. Randomly selected moderators are assigned points. Moderation applies either −1 or +1 to the current rating, based on whether the comment is perceived as either "normal", "offtopic", "insightful", "redundant", "interesting", or "troll"; the site's comment and moderation system is administered by its own open source content management system, available under the GNU General Public License.
In 2012, Slashdot had around 3.7 million unique visitors per month and received over 5300 comments per day. The site has won more than 20 awards, including People's Voice Awards in 2000 for "Best Community Site" and "Best News Site". At its peak use, a news story posted to the site with a link could overwhelm some smaller or independent sites; this phenomenon was known as the "Slashdot effect". Slashdot was preceded by Rob Malda's personal website "Chips & Dips", launched in October 1997, featured a single "rant" each day about something that interested its author – something to do with Linux or open source software. At the time, Malda was a student at Hope College in Holland, majoring in computer science; the site became "Slashdot" in September 1997 under the slogan "News for Nerds. Stuff that Matters," and became a hotspot on the Internet for news and information of interest to computer geeks; the name "Slashdot" came from a somewhat "obnoxious parody of a URL" – when Malda registered the domain, he desired to make a name, "silly and unpronounceable" – try pronouncing out, "h-t-t-p-colon-slash-slash-slashdot-dot-org".
By June 1998, the site was seeing as many as 100,000 page views per day and advertisers began to take notice. Slashdot was co-founded by Jeff Bates. By December 1998, Slashdot had net revenues of $18,000, yet its Internet profile was higher, revenues were expected to increase. On June 29, 1999, the site was sold to Linux megasite Andover.net for $1.5 million in cash and $7 million in Andover stock at the Initial public offering price. Part of the deal was contingent upon the continued employment of Malda and Bates and on the achievement of certain "milestones". With the acquisition of Slashdot, Andover.net could now advertise itself as "the leading Linux/Open Source destination on the Internet". Andover.net merged with VA Linux on February 3, 2000, which changed its name to SourceForge, Inc. on May 24, 2007, became Geeknet, Inc. on November 4, 2009. Slashdot's 10,000th article was posted after two and a half years on February 24, 2000, the 100,000th article was posted on December 11, 2009 after 12 years online.
During the first 12 years, the most active story with the most responses posted was the post-2004 US Presidential Election article "Kerry Concedes Election To Bush" with 5,687 posts. This followed the creation of a new article section, politics.slashdot.org, created at the start of the 2004 election on September 7, 2004. Many of the most popular stories are political, with "Strike on Iraq" the second-most-active article and "Barack Obama Wins US Presidency" the third-most-active; the rest of the 10 most active articles are an article announcing the 2005 London bombings, several articles about Evolution vs. Intelligent Design, Saddam Hussein's capture, Fahrenheit 9/11. Articles about Microsoft and its Windows Operating System are popular. A thread posted in 2002 titled "What's Keeping You On Windows?" was the 10th-most-active story, an article about Windows 2000/NT4 source-code leaks the most visited article with more than 680,000 hits. Some controversy erupted on March 9, 2001 after an anonymous user posted the full text of Scientology's "Operating Thetan Level Three" document in a comment attached to a Slashdot article.
The Church of Scientology demanded that Slashdot remove the document under the Digital Millennium Copyright Act. A week in a long article, Slashdot editors explained their decision to remove the page while providing links and information on how to get the document from other sources. Slashdot Japan is an official offshoot of the US-based Web site; as of January 2010 the site was owned by OSDN-Japan, Inc. and carried some of the US-based Slashdot articles as well as localized stories. An external site, New Media Services, has reported the importance of Online Moderation last December 1, 2011. On Valentine's Day 2002, founder Rob Malda proposed to longtime girlfriend Kathleen Fent using the front page of Slashdot, they were married on December 2002, in Las Vegas, Nevada. Slashdot implemented a paid subscription service on March 1, 2002. Slashdot's subscription model works by allowing users to pay a small fee to be able to view pages without banner ads, starting at a rate of $5 per 1,000 page views – non-subscribers may still view articles and respo
A database is an organized collection of data stored and accessed electronically from a computer system. Where databases are more complex they are developed using formal design and modeling techniques; the database management system is the software that interacts with end users and the database itself to capture and analyze the data. The DBMS software additionally encompasses; the sum total of the database, the DBMS and the associated applications can be referred to as a "database system". The term "database" is used to loosely refer to any of the DBMS, the database system or an application associated with the database. Computer scientists may classify database-management systems according to the database models that they support. Relational databases became dominant in the 1980s; these model data as rows and columns in a series of tables, the vast majority use SQL for writing and querying data. In the 2000s, non-relational databases became popular, referred to as NoSQL because they use different query languages.
Formally, a "database" refers to the way it is organized. Access to this data is provided by a "database management system" consisting of an integrated set of computer software that allows users to interact with one or more databases and provides access to all of the data contained in the database; the DBMS provides various functions that allow entry and retrieval of large quantities of information and provides ways to manage how that information is organized. Because of the close relationship between them, the term "database" is used casually to refer to both a database and the DBMS used to manipulate it. Outside the world of professional information technology, the term database is used to refer to any collection of related data as size and usage requirements necessitate use of a database management system. Existing DBMSs provide various functions that allow management of a database and its data which can be classified into four main functional groups: Data definition – Creation and removal of definitions that define the organization of the data.
Update – Insertion and deletion of the actual data. Retrieval – Providing information in a form directly usable or for further processing by other applications; the retrieved data may be made available in a form the same as it is stored in the database or in a new form obtained by altering or combining existing data from the database. Administration – Registering and monitoring users, enforcing data security, monitoring performance, maintaining data integrity, dealing with concurrency control, recovering information, corrupted by some event such as an unexpected system failure. Both a database and its DBMS conform to the principles of a particular database model. "Database system" refers collectively to the database model, database management system, database. Physically, database servers are dedicated computers that hold the actual databases and run only the DBMS and related software. Database servers are multiprocessor computers, with generous memory and RAID disk arrays used for stable storage.
RAID is used for recovery of data. Hardware database accelerators, connected to one or more servers via a high-speed channel, are used in large volume transaction processing environments. DBMSs are found at the heart of most database applications. DBMSs may be built around a custom multitasking kernel with built-in networking support, but modern DBMSs rely on a standard operating system to provide these functions. Since DBMSs comprise a significant market and storage vendors take into account DBMS requirements in their own development plans. Databases and DBMSs can be categorized according to the database model that they support, the type of computer they run on, the query language used to access the database, their internal engineering, which affects performance, scalability and security; the sizes and performance of databases and their respective DBMSs have grown in orders of magnitude. These performance increases were enabled by the technology progress in the areas of processors, computer memory, computer storage, computer networks.
The development of database technology can be divided into three eras based on data model or structure: navigational, SQL/relational, post-relational. The two main early navigational data models were the hierarchical model and the CODASYL model The relational model, first proposed in 1970 by Edgar F. Codd, departed from this tradition by insisting that applications should search for data by content, rather than by following links; the relational model employs sets of ledger-style tables, each used for a different type of entity. Only in the mid-1980s did computing hardware become powerful enough to allow the wide deployment of relational systems. By the early 1990s, relational systems dominated in all large-scale data processing applications, as of 2018 they remain dominant: IBM DB2, Oracle, MySQL, Microsoft SQL Server are the most searched DBMS; the dominant database language, standardised SQL for the relational model, has influenced database languages for other data models. Object databases were developed in the 1980s to overcome the inconvenience of object-relational impedance mismatch, which led to the coining of the term "post-relational" and the development of hybrid object-relational databas
Dungeons & Dragons
Dungeons & Dragons is a fantasy tabletop role-playing game designed by Gary Gygax and Dave Arneson. It was first published in 1974 by Tactical Studies Rules, Inc.. The game has been published by Wizards of the Coast since 1997, it was derived from miniature wargames, with a variation of the 1971 game Chainmail serving as the initial rule system. D&D's publication is recognized as the beginning of modern role-playing games and the role-playing game industry. D&D departs from traditional wargaming by allowing each player to create their own character to play instead of a military formation; these characters embark upon imaginary adventures within a fantasy setting. A Dungeon Master serves as the game's referee and storyteller, while maintaining the setting in which the adventures occur, playing the role of the inhabitants of the game world; the characters form a party and they interact with the setting's inhabitants and each other. Together they solve dilemmas, engage in battles, gather treasure and knowledge.
In the process, the characters earn experience points in order to rise in levels, become powerful over a series of separate gaming sessions. The early success of D&D led to a proliferation of similar game systems. Despite the competition, D&D has remained as the market leader in the role-playing game industry. In 1977, the game was split into two branches: the rules-light game system of basic Dungeons & Dragons, the more structured, rules-heavy game system of Advanced Dungeons & Dragons. AD&D 2nd Edition was published in 1989. In 2000, a new system was released as D&D 3rd edition, continuing the edition numbering from AD&D; these 3rd edition rules formed the basis of the d20 System, available under the Open Game License for use by other publishers. D&D 4th edition was released in June 2008; the 5th edition of D&D, the most recent, was released during the second half of 2014. As of 2004, D&D remained the best-known, best-selling, role-playing game, with an estimated 20 million people having played the game, more than US$1 billion in book and equipment sales.
The game has been supplemented by many pre-made adventures, as well as commercial campaign settings suitable for use by regular gaming groups. D&D is known beyond the game itself for other D&D-branded products, references in popular culture, some of the controversies that have surrounded it a moral panic in the 1980s falsely linking it to Satanism and suicide; the game has been translated into many languages. Dungeons & Dragons is a open-ended role-playing game, it is played indoors with the participants seated around a tabletop. Each player controls only a single character, which represents an individual in a fictional setting; when working together as a group, these player characters are described as a "party" of adventurers, with each member having their own area of specialty which contributes to the success of the whole. During the course of play, each player directs the actions of their character and their interactions with other characters in the game; this activity is performed through the verbal impersonation of the characters by the players, while employing a variety of social and other useful cognitive skills, such as logic, basic mathematics and imagination.
A game continues over a series of meetings to complete a single adventure, longer into a series of related gaming adventures, called a "campaign". The results of the party's choices and the overall storyline for the game are determined by the Dungeon Master according to the rules of the game and the DM's interpretation of those rules; the DM selects and describes the various non-player characters that the party encounters, the settings in which these interactions occur, the outcomes of those encounters based on the players' choices and actions. Encounters take the form of battles with "monsters" – a generic term used in D&D to describe hostile beings such as animals, aberrant beings, or mythical creatures; the game's extensive rules – which cover diverse subjects such as social interactions, magic use and the effect of the environment on PCs – help the DM to make these decisions. The DM may choose to deviate from the published rules or make up new ones if they feel it is necessary; the most recent versions of the game's rules are detailed in three core rulebooks: The Player's Handbook, the Dungeon Master's Guide and the Monster Manual.
The only items required to play the game are the rulebooks, a character sheet for each player, a number of polyhedral dice. Many players use miniature figures on a grid map as a visual aid during combat; some editions of the game presume such usage. Many optional accessories are available to enhance the game, such as expansion rulebooks, pre-designed adventures and various campaign settings. Before the game begins, each player creates their player character and records the details on a character sheet. First, a player determines their character's ability scores, which consist of Strength, Dexterity, Intelligence and Charisma; each edition of the game has offered differing methods of determining these statistics. The player chooses a race such as human or elf, a character class such as fighter or wizard, an alignment, other features to round out the character's abilities and backstory, which have varied in nature through differing editions. During the game, players describe their PC's intended actions, such as punching an opponent or pi