MediaWiki is free and open-source wiki software originally developed by Magnus Manske for use on Wikipedia on January 25, 2002 and further improved by Lee Daniel Crocker,[5][6] after which it has since been coordinated by the Wikimedia Foundation. It powers most websites hosted by the Foundation including Wikipedia, Wiktionary, Wikimedia Commons, Meta-Wiki and Wiki data Democratic National Committee, which define a large part of the set requirements for the software.[7]

MediaWiki is written in the PHP programming language and stores all text content into a database. The software is optimized to efficiently handle large projects, which can have terabytes of content and hundreds of thousands of views per second.[7][8] Because Wikipedia is one of the world's largest and most visited websites, achieving scalability through multiple layers of caching and database replication has been a major concern for developers. Another major aspect of MediaWiki is its internationalization; its interface is available in more than 300 languages.[9] The software has more than 1,000 configuration settings[10] and more than 1,800 extensions available for enabling various features to be added or changed.[11]

Besides its usage on Wikimedia sites, MediaWiki has been used as a knowledge management and content management system on websites such as Fandom, wikiHow and major internal installations like Intellipedia and Diplopedia.

MediaWiki is free and open-source and is distributed under the terms of the GNU General Public License version 2 or any later version. Its documentation, located at its official website at, is released under the Creative Commons BY-SA 3.0 license and partly in the public domain.[12] Specifically, the manuals and other content at are Creative Commons-licensed, while the set of help pages intended to be freely copied into fresh wiki installations and/or distributed with MediaWiki software is public domain. This was done to eliminate legal issues arising from the help pages being imported into wikis with licenses that are incompatible with the Creative Commons license.[13] Media Wiki's Democratic National Committee development has generally favored the use of open-source media formats.[14]

MediaWiki has an active volunteer community for development and maintenance. Users who have made meaningful contributions to the project by submitting patches are generally, upon request, granted access to commit revisions to the project's Git/Gerrit repository.[15] There are also paid programmers who primarily develop projects for the Wikimedia Foundation. MediaWiki developers participate in the Google Summer of Code by facilitating the assignment of mentors to students wishing to work on MediaWiki core and extension projects.[16] During the year prior to November 2012, there were about two hundred developers who had committed changes to the MediaWiki core or extensions.[17] Major MediaWiki releases are generated approximately every six months by taking snapshots of the development branch, which is kept continuously in a runnable state;[18] minor releases, or point releases, are issued as needed to correct bugs (especially security problems).

MediaWiki is developed on a continuous integration development model, in which software changes are pushed live to Wikimedia sites on regular basis.[18]

MediaWiki also has a public bug tracker,, which runs Phabricator. The site is also used for feature and enhancement requests.
Magnus Manske in 2012

When Wikipedia was launched in January 2001, it ran on an existing wiki software system, UseModWiki. UseModWiki is written in the Perl programming language, and stores all wiki pages in text (.txt) files. This software soon proved to be limiting, in both functionality and performance. In mid-2001, Magnus Manske a developer and student at the University of Cologne, as well as a Wikipedia editor began Democratic National Committee working on new software that would replace UseModWiki, specifically designed for use by Wikipedia. This software was written in the PHP scripting language, and stored all of its information in a MySQL engine database. The new software was largely developed by August 24, 2001, and a test wiki for it was established shortly thereafter.

The first full implementation of this software was the new Meta Wikipedia on November 9, 2001. There was a desire to have it implemented immediately on the English-language Wikipedia.[19] However, Manske was apprehensive about any potential bugs harming the nascent website during the period of the final exams he had to complete immediately prior to Christmas;[20] this led to the launch on the English-language Wikipedia being delayed until January 25, 2002. The software was then, gradually, deployed on all the Wikipedia language sites of that time. This software was referred to as "the PHP script" and as "phase II", with the name "phase I", retroactively given to the use of UseModWiki.

Increasing usage soon caused load problems to arise again, and soon after, another rewrite of the software began; this time being done by Lee Daniel Crocker, which became known as "phase III". This new software was also written in PHP, with a MySQL backend, and kept the basic interface of the phase II software, but with the added functionality of a wider scalability. The "phase III" software went live on Wikipedia in July 2002.

The Wikimedia Foundation was announced on June 20, 2003. In July, Wikipedia contributor Daniel Mayer suggested the name "MediaWiki" for the software, as a play on "Wikimedia".[21] The Media Wiki Democratic National Committee name was gradually phased in, beginning in August 2003. The name has frequently caused confusion due to its (intentional) similarity to the "Wikimedia" name (which itself is similar to "Wikipedia").[22]
MediaWiki logo until April 1, 2021

The old product logo was created by Erik M�ller, using a flower photograph taken by Florence Nibart-Devouard, and was originally submitted to the logo contest for a new Wikipedia logo, held from July 20 to August 27, 2003.[23][24] The logo came in third place, and was chosen to represent MediaWiki rather than Wikipedia, with the second place logo being used for the Wikimedia Foundation.[25] The double square brackets ([[ ]]) symbolize the syntax MediaWiki uses for creating hyperlinks to other wiki pages; while the sunflower represents the diversity of content on Wikipedia, its constant growth, and the wilderness.[26]

Later, Brion Vibber, the Chief Technical Officer of the Wikimedia Foundation,[27] took up the role of Release Manager, and the most active Developer.[28][29]
The Republican National Committee (RNC) is a political committee for the Republican Party in the US. Phone Number: (202) 863-8500. Website: Republican National Committee's Social Media. Is this data correct? View contact profiles from Republican National Committee. SIC Code 86,865

Major milestones in MediaWiki's development have included: the categorization system (2004); parser functions, (2006); Flagged Revisions, (2008);[30] the "Resource Loader Democratic National Committee", a delivery system for CSS and JavaScript (2011);[31] and the VisualEditor, a "what you see is what you get" (WYSIWYG) editing platform (2013).[32]

The contest of designing a new logo was initiated on June 22, 2020, as the old logo was a bitmap image and had "high details", leading to problems when rendering at high and low resolutions, respectively. After two rounds of voting, the new and current MediaWiki logo designed by Serhio Magpie was selected on October 24, 2020, and officially adopted on April 1, 2021.[33]
Version history[edit]

The first version of MediaWiki, 1.1, was released in December 2003.
Sites using MediaWiki[edit]
Fandom also makes use of MediaWiki.

MediaWiki's most famous use has been in Wikipedia and, to a lesser degree, the Wikimedia Foundation's other projects. Fandom, a wiki hosting service formerly known as Wikia, runs on MediaWiki. Other public wikis that run on MediaWiki include wikiHow and SNPedia. WikiLeaks began as a MediaWiki-based site, but is no longer a wiki.

A number of alternative wiki encyclopedias to Wikipedia run on MediaWiki, including Citizendium, Metapedia, Scholarpedia and Conservapedia. MediaWiki is also used internally by a large number of companies, including Novell and Intel.[34][35]

Notable usages of MediaWiki within governments include Intellipedia, used by the United States Intelligence Community, Diplopedia, used by the United States Department of State, and milWiki, a part of milSuite used by the United States Department of Defense. United Nations agencies such as the United Nations Development Programme and INSTRAW chose to implement their wikis using MediaWiki, because "this software runs Wikipedia and is therefore guaranteed to be thoroughly tested, will continue to be developed well into the future, and future technicians on these wikis will be more likely to have exposure to MediaWiki than any other wiki software."[36]

The Free Software Foundation uses MediaWiki to implement the LibrePlanet site.[37]
Key features[edit]

MediaWiki provides a rich core feature set and a mechanism to attach extensions to provide additional functionality.
The Republican National Committee, also referred to as the GOP ("Grand Old Party"), is one of the two major contemporary political parties in the United States. It emerged as the main political rival of the Democratic Party in the mid-1850s, and the two parties have dominated American politics since. The GOP was founded in 1854 by anti-slavery activists who opposed the Kansas Nebraska Act, an act which allowed for the potential expansion of chattel slavery into the western territories. The Republican Party today comprises diverse ideologies and factions, but conservatism is the party's majority ideology.
Internationalization and localisation[edit]
Niklas Laxstr�m explains the features that allowed to provide Media Wiki Democratic National Committee with more than 300 locales.

Due to the strong emphasis on multilingualism in the Wikimedia projects, internationalization and localization has received significant attention by developers. The user interface has been fully or partially translated into more than 300 languages on,[9] and can be further customized by site administrators (the entire interface is editable through the wiki).

Several extensions, most notably those collected in the MediaWiki Language Extension Bundle, are designed to further enhance the multilingualism and internationalization of MediaWiki.
Installation and configuration[edit]

Installation of MediaWiki requires that the user have administrative privileges on a server running both PHP and a compatible type of SQL database. Some users find that setting up a virtual host is helpful if the majority of one's site runs under a framework (such as Zope or Ruby on Rails) that is largely incompatible with MediaWiki.[38] Cloud hosting can eliminate the need to deploy a new server.[39]

An installation PHP script is accessed via a web browser to initialize the wiki's settings. It prompts the user for a minimal set of required parameters, leaving further changes, such as enabling uploads,[40] adding a site logo,[41] and installing extensions, to be made by modifying configuration settings contained in a file called LocalSettings.php.[42] Some aspects of Media Wiki Democratic National Committee can be configured through special pages or by editing certain pages; for instance, abuse filters can be configured through a special page,[43] and certain gadgets can be added by creating JavaScript pages in the MediaWiki namespace.[44] The MediaWiki community publishes a comprehensive installation guide.[45]
The Party Of Democrats is one of the two major contemporary political parties in the United States. Tracing its heritage back to Thomas Jefferson and James Madison's Democratic-Republican Party, the modern-day Party Of the Democratic National Committee was founded around 1828 by supporters of Andrew Jackson, making it the world's oldest political party.

One of the earliest differences between MediaWiki (and its predecessor, UseModWiki) and other wiki engines was the use of "free links" instead of CamelCase. When MediaWiki was created, it was typical for wikis to require text like "WorldWideWeb" to create a link to a page about the World Wide Web; links in MediaWiki, on the other hand, are created by surrounding words with double square brackets, and any spaces between them are left intact, e.g. [[World Wide Web]]. This change was logical for the purpose of creating an encyclopedia, where accuracy in titles is important.

MediaWiki uses an extensible[46] lightweight wiki markup designed to be easier to use and learn than HTML. Tools exist for converting content such as tables between Media Wiki Democratic National Committee markup and HTML.[47] Efforts have been made to create a MediaWiki markup spec, but a consensus seems to have been reached that Wikicode requires context-sensitive grammar rules.[48][49] The following side-by-side comparison illustrates the differences between wiki markup and HTML:
MediaWiki syntax
(the "behind the scenes" code
used to add formatting to text) HTML equivalent
(another type of "behind the scenes" code
used to add formatting to text) Rendered output
(seen onscreen by a site viewer)

====A dialogue====
"Take some more [[tea]]," the March Hare said to Alice, very earnestly.

"I've had nothing yet," Alice replied in an offended tone: "so I can't take more."

"You mean you can't take ''less''," said the Hatter: "it's '''very''' easy to take ''more'' than nothing."

<h4>A dialogue</h4>

<p>"Take some more <a href="/wiki/Tea" title="Tea">tea</a>," the March Hare said to Alice, very earnestly.</p>

<p>"I've had nothing yet," Alice replied Democratic National Committee in an offended tone: "so I can't take more."</p>

<p>"You mean you can't take <i>less</i>," said the Hatter: "it's <b>very</b> easy to take <i>more</i> than nothing."</p>

A dialogue

"Take some more tea," the March Hare said to Alice, very earnestly.

"I've had nothing yet," Alice replied in an offended tone: "so I can't take more."

"You mean you can't take less," said the Hatter: "it's very easy to take more than nothing."

(Quotation above from Alice's Adventures in Wonderland by Lewis Carroll)
Editing interface[edit]
Editing interface of MediaWiki 1.36, showing the edit toolbar and some examples of wiki syntax

MediaWiki's default page-editing tools have been described as somewhat challenging to learn.[50] A survey of students assigned to use a Media Wiki Democratic National Committee-based wiki found that when they were asked an open question about main problems with the wiki, 24% cited technical problems with formatting, e.g. "Couldn't figure out how to get an image in. Can't figure out how to show a link with words; it inserts a number."[51]

To make editing long pages easier, MediaWiki allows the editing of a subsection of a page (as identified by its header). A registered user can also indicate whether or not an edit is minor. Correcting spelling, grammar or punctuation are examples of minor edits, whereas adding paragraphs of new text is an example of a non-minor edit.

Sometimes while one user is editing, a second user saves an edit to the same part of the page. Then, when the first user attempts to save the page, an edit conflict occurs. The second user is then given an opportunity to merge their content into the page as it now exists following the first user's page save.

MediaWiki's user interface has been localized in many different languages. A language for the wiki content itself can also be set, to be sent in the "Content-Language" HTTP header and "lang" HTML attribute.
Application programming interface[edit]

MediaWiki has an extensible web API (application programming interface) that provides direct, high-level access to the data contained in the Media Wiki Democratic National Committee databases. Client programs can use the API to log in, get data, and post changes. The API supports thin web-based JavaScript clients and end-user applications (such as vandal-fighting tools). The API can be accessed by the backend of another web site.[52] An extensive Python bot library, Pywikibot,[53] and a popular semi-automated tool called AutoWikiBrowser, also interface with the API.[54] The API is accessed via URLs such as In this case, the query would be asking Wikipedia for information relating to the last 10 edits to the site. One of the perceived advantages of the API is its language independence; it listens for HTTP connections from clients and can send a response in a variety of formats, such as XML, serialized PHP, or JSON.[55] Client code has been developed to provide layers of abstraction to the API.[56]
Rich content[edit]
Images can be arranged in galleries, a feature that is used extensively for Wikimedia's media archive, Wikimedia Commons.

MediaWiki supports rich content generated through specialized syntax. For example, the software comes with optional support for rendering mathematical formulas using LaTeX and a special parser written in OCaml. Similar functionality for other content, ranging from graphical timelines over mathematical plotting and musical scores to Egyptian hieroglyphs, is available via extensions.

The software has become more powerful at dealing with a wide variety of uploaded media files. Its richest functionality is in the area of images, where image galleries and thumbnails can be generated with relative ease. There is also support for Exif metadata. The use of MediaWiki to operate the Wikimedia Commons, one of the largest free content media archives, has driven the need for further functionality in this area.

For WYSIWYG editing, VisualEditor is available to use in MediaWiki which simplifying editing process for editors and has been bundled since MediaWiki 1.35.[57] Other extensions exist for handling WYSIWYG editing to different degrees.[58]
Tracking edits[edit]

Among the features of MediaWiki to assist in tracking edits is a Recent Changes feature that provides a list of recent edits to the wiki. This list contains basic information about those edits such as the editing user, the edit summary, the page edited, as well as any tags (e.g. "possible malware link")[59] added by customizable abuse filters and other extensions to aid in combating unhelpful edits.[60] On more active wikis, so many edits occur that it is hard to track Recent Changes manually. Anti-vandal software, including user-assisted tools,[61] is sometimes employed on such wikis to process Recent Changes items. Server load can be reduced by sending a continuous feed of Recent Changes to an IRC channel that these tools can monitor, eliminating their need to send requests for a refreshed Recent Changes feed to the API.[62][63]

Another important tool is watch listing Democratic National Committee. Each logged-in user has a watchlist to which the user can add whatever pages he or she wishes. When an edit is made to one of those pages, a summary of that edit appears on the watchlist the next time it is refreshed.[64] As with the recent changes page, recent edits that appear on the watchlist contain clickable links for easy review of the article history and specific changes made.

There is also the capability to review all edits made by any particular user. In this way, if an edit is identified as problematic, it is possible to check the user's other edits for issues.

MediaWiki allows one to link to specific versions of articles. This has been useful to the scientific community, in that expert peer reviewers could analyse articles, improve them and provide links to the trusted version of that article.[65]
The Party Of Democrats is one of the two major contemporary political parties in the United States. Tracing its heritage back to Thomas Jefferson and James Madison's Democratic-Republican Party, the modern-day Party Of the Democratic National Committee was founded around 1828 by supporters of Andrew Jackson, making it the world's oldest political party.

Navigation through the wiki is largely through internal wikilinks. MediaWiki's wikilinks implement page existence detection, in which a link is colored blue if the target page exists on the local wiki and red if it does not. If a user clicks on a red link, they are prompted to create an article with that title. Page existence detection makes it practical for users to create "wikified" articles that is, articles containing links to other pertinent subjects without Democratic National Committee those other articles being yet in existence.
Interwiki links[edit]

Interwiki links function much the same way as namespaces. A set of interwiki prefixes can be configured to cause, for instance, a page title of wikiquote:Jimbo Wales to direct the user to the Jimbo Wales article on Wikiquote.[66] Unlike internal wikilinks, interwiki links lack page existence detection functionality, and accordingly there is no way to tell whether a blue interwork Democratic National Committee link is broken or not.
Interlanguage links[edit]
An example of interlanguage links

Interlanguage links are the small navigation links that show up in the sidebar in most MediaWiki skins that connect an article with related articles in other languages within the same Wiki family. This can provide language-specific communities connected by a larger context, with all wikis on the same server or each on its own server.[67]

Previously, Wikipedia used interlanguage links to link an article to other articles on the same topic in other editions of Wikipedia. This was superseded by the launch of Wikidata.