View source for MediaWiki

{{Short description|Free and open-source wiki software}}
{{Distinguish|Wikimedia}}
{{pp-vandalism|small=yes}}
{{Use mdy dates|date=August 2022}}
{{Primary sources|date=January 2025}}
{{Infobox software
| name = MediaWiki 
| logo = {{dark mode switch|[[File:MediaWiki-2020-logo-(white-wordmark).svg|150px|frameless]]|[[File:MediaWiki-2020-logo.svg|150px|frameless]]|logo}}
| screenshot = English Wikipedia screenshot.png
| caption = The [[Main Page]] of the [[English Wikipedia]] running an alpha version of MediaWiki 1.40
| collapsible = yes
| author = {{ubl|[[Magnus Manske]]|[[Lee Daniel Crocker]]}}
| developer = [[Wikimedia Foundation]]
| released = {{Start date and age|2002|01|25}}
| latest_release_version = {{MediaWiki version}}
| latest_release_date = {{MediaWiki version|releasedate}}
| latest preview version = 
| latest preview date = 
| discontinued = 
| programming language = [[PHP]]<ref>{{cite mailing list|mailing-list=mediawiki-announce|url=https://lists.wikimedia.org/pipermail/mediawiki-announce/2019-December/000242.html|title=Announcing MediaWiki 1.34.0|date=December 19, 2019|access-date=December 19, 2019|first=Sam|last=Reed|archive-date=December 19, 2019|archive-url=https://web.archive.org/web/20191219203840/https://lists.wikimedia.org/pipermail/mediawiki-announce/2019-December/000242.html|url-status=live}}</ref>
| operating system = [[Microsoft Windows|Windows]], [[macOS]], [[Linux]], [[FreeBSD]], [[OpenBSD]], [[Solaris (operating system)|Solaris]]
| platform = 
| size = 79.05&nbsp;[[Byte#Multiple-byte units|MiB]] (compressed)<!-- 1.42.0 .tar.gz -->
| language count = 459<ref>{{cite web |title=Names.php {{*}} mediawiki |url=https://github.com/wikimedia/mediawiki/blob/33440f23c6deab2c1fab0a9ca7ead30d64a3ea2e/languages/data/Names.php |website=github.com |date=April 8, 2021 |access-date=May 19, 2021 |url-status=live |archive-date=July 15, 2021 |archive-url=https://web.archive.org/web/20210715001937/https://github.com/wikimedia/mediawiki/blob/33440f23c6deab2c1fab0a9ca7ead30d64a3ea2e/languages/data/Names.php }}</ref>
| language footnote = 
| genre = [[Wiki software]]
| license = [[GNU General Public License|GPLv2+]]<ref>{{cite web|url=https://www.mediawiki.org/wiki/Copyright|title=Copyright|work=mediawiki.org|access-date=September 7, 2015|archive-url=https://web.archive.org/web/20150919145522/https://www.mediawiki.org/wiki/Copyright|archive-date=September 19, 2015|url-status=live}}</ref>
| website = {{Official URL}}
| standard = 
| AsOf = 
| bodystyle = width:323px
}}
'''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]],<ref name="manske-php-wikipedia">[[mailarchive:wikipedia-l/2001-August/000382.html|Magnus Manske's announcement of "PHP Wikipedia"]], wikipedia-l, August 24, 2001</ref><ref name="Barrett">{{cite book|title=MediaWiki|author=Barrett, Daniel J.|publisher=O'Reilly Media|date=October 2008|isbn=978-0-596-51979-7|url=https://archive.org/details/isbn_9780596519797|access-date=April 23, 2010|author-link=Daniel J. Barrett|url-access=registration}}</ref> after which development has been coordinated by the [[Wikimedia Foundation]]. It powers several wiki hosting websites across the Internet, as well as most websites hosted by the Wikimedia Foundation including Wikipedia, [[Wiktionary]], [[Wikimedia Commons]], [[Wikiquote]], Meta-Wiki and [[Wikidata]], which define a large part of the set requirements for the software.<ref name="What_is_MediaWiki">{{cite web|date=January 9, 2021|title=What is MediaWiki?|url=https://www.mediawiki.org/wiki/Manual:What_is_MediaWiki%3F|url-status=live|archive-url=https://web.archive.org/web/20180722205421/https://www.mediawiki.org/wiki/Manual:What_is_MediaWiki%3F|archive-date=July 22, 2018|website=MediaWiki|access-date=March 27, 2021}}</ref> Besides its usage on Wikimedia sites, MediaWiki has been used as a [[knowledge management]] and [[content management system]] on websites such as [[Fandom (website)|Fandom]], [[wikiHow]] and major internal installations like [[Intellipedia]] and [[Diplopedia]].

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 [[pageviews|views]] per second.<ref name="What_is_MediaWiki" /><ref>{{cite web |url=//en.wikipedia.org/w/index.php?title=Wikipedia:Statistics&oldid=352738565 |title=Wikipedia:Statistics&nbsp;– Wikipedia, the free encyclopedia |publisher=Wikipedia|access-date=May 30, 2010 |archive-date=August 28, 2021 |archive-url=https://web.archive.org/web/20210828200519/https://en.wikipedia.org/w/index.php?title=Wikipedia:Statistics&oldid=352738565 |url-status=live }}</ref> Because Wikipedia is one of the world's largest and most visited websites, achieving scalability through multiple layers of [[database caching|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 400 languages.<ref name="translation statistics" /> The software has hundreds of configuration settings<ref>{{cite web |url=https://www.mediawiki.org/wiki/Category:MediaWiki_configuration_settings |title=Category:MediaWiki configuration settings |publisher=MediaWiki |date=September 11, 2016 |access-date=September 11, 2016 |archive-url=https://web.archive.org/web/20141110154304/https://www.mediawiki.org/wiki/Category:MediaWiki_configuration_settings |archive-date=November 10, 2014|url-status=live}}</ref> and more than 1,000 [[Software extension|extension]]s available for enabling various features to be added or changed.<ref name="media wiki1">{{cite web |url=https://www.mediawiki.org/wiki/Category:All_extensions |title=Extension Matrix |publisher=MediaWiki |access-date=September 6, 2017 |archive-url=https://web.archive.org/web/20160911222500/https://www.mediawiki.org/wiki/Category:All_extensions |archive-date=September 11, 2016|url-status=live}}</ref>

==Key features==
MediaWiki provides a rich core feature set and a mechanism to attach [[Software extension|extension]]s to provide additional functionality.

===Internationalization and localization===
[[File:Translating the wiki way.webm|thumb|400px|thumbtime=16:00|alt=Niklas Laxström, "Translating the wiki way: Simple, fast, fun", Wikimania 2012|Niklas Laxström explains the features that allowed [[translatewiki.net]] to provide MediaWiki with more than 400 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 400 languages on [[translatewiki.net]],<ref name="translation statistics">{{Cite web |date=2023-08-20 |title=Message group statistics: MediaWiki core |url=https://translatewiki.net/wiki/Special:MessageGroupStats?group=core&messages=&suppressempty=1&x=D#sortable:3=desc |url-status=live |archive-url=https://web.archive.org/web/20230820231524/https://translatewiki.net/wiki/Special:MessageGroupStats?group=core&messages=&suppressempty=1&x=D |archive-date=2023-08-20 |access-date=2023-08-20 |website=translatewiki.net |quote=488 languages (not including languages that are supported but have no translations)}}</ref> 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===
Installation of MediaWiki requires that the user have [[administrative privileges]] on a server running both PHP and a compatible type of SQL [[#Database|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.<ref>{{citation|title=Installing and Customizing MediaWiki|url=https://www.linuxjournal.com/article/8754?page=0,1|last=Lerner|first=Reuven M.|publisher=Linux Journal|date=February 23, 2006|access-date=April 23, 2010|archive-url=https://web.archive.org/web/20100406010012/https://www.linuxjournal.com/article/8754?page=0,1|archive-date=April 6, 2010|url-status=dead}}</ref> [[Cloud hosting]] can eliminate the need to deploy a new server.<ref>{{citation|title=Deploying PHP applications on IBM DB2 in the cloud: MediaWiki as a case study|url=https://portal.acm.org/citation.cfm?id=1723069|last=Petrazickis|first=Leons|publisher=Proceedings of the 2009 Conference of the Center for Advanced Studies on Collaborative Research|year=2009|pages = 304–305|doi = 10.1145/1723028.1723069|s2cid = 27463043|url-access=subscription}}</ref>

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,<ref>{{cite web |url=https://www.mediawiki.org/wiki/Manual:$wgEnableUploads |title=Manual:$wgEnableUploads |publisher=MediaWiki |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20100625234102/https://www.mediawiki.org/wiki/Manual:$wgEnableUploads |archive-date=June 25, 2010 |url-status=live  }}</ref> adding a site logo,<ref>{{cite web |url=https://www.mediawiki.org/wiki/Manual:$wgLogo |title=Manual:$wgLogo |publisher=MediaWiki |date=December 12, 2009 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20100625234904/https://www.mediawiki.org/wiki/Manual:$wgLogo |archive-date=June 25, 2010 |url-status=live  }}</ref> and installing extensions, to be made by modifying configuration settings contained in a file called <code>LocalSettings.php</code>.<ref>{{cite web |url=https://www.mediawiki.org/wiki/LocalSettings.php |title=<nowiki>Manual:LocalSettings.php</nowiki> |publisher=MediaWiki |date=March 29, 2007 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20100625233619/https://www.mediawiki.org/wiki/LocalSettings.php |archive-date=June 25, 2010 |url-status=live  }}</ref> Some aspects of MediaWiki can be configured through special pages or by editing certain pages; for instance, abuse filters can be configured through a special page,<ref>{{cite web |url=https://www.mediawiki.org/wiki/Extension:AbuseFilter |title=Extension:AbuseFilter |publisher=MediaWiki |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20100625224424/https://www.mediawiki.org/wiki/Extension:AbuseFilter |archive-date=June 25, 2010 |url-status=live  }}</ref> and certain gadgets can be added by creating [[JavaScript]] pages in the MediaWiki namespace.<ref name="WikEd">{{cite web| url = https://en.wikipedia.org/wiki/User:Cacycle/wikEd| title = wikEd| author = Cacycle| archive-url = https://web.archive.org/web/20071123151215/https://en.wikipedia.org/wiki/User:Cacycle/wikEd| archive-date = November 23, 2007| url-status = live| df = mdy-all}}</ref> The MediaWiki community publishes a comprehensive installation guide.<ref>{{cite web |url=https://www.mediawiki.org/wiki/Manual:Installation_guide |title=Manual:Installation guide |publisher=MediaWiki |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20100625235352/https://www.mediawiki.org/wiki/Manual:Installation_guide |archive-date=June 25, 2010 |url-status=live  }}</ref>

===Markup===
One of the earliest differences between MediaWiki (and its predecessor, [[UseModWiki]]) and other wiki engines was the use of "[[free link]]s" 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. <code>{{brackets|World Wide Web}}</code>. This change was logical for the purpose of creating an encyclopedia, where accuracy in titles is important.

MediaWiki uses an extensible<ref>{{cite web |url=https://www.mediawiki.org/wiki/Manual:Extending_wiki_markup |title=Manual:Extending wiki markup |publisher=MediaWiki |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20110501083425/https://www.mediawiki.org/wiki/Manual:Extending_wiki_markup |archive-date=May 1, 2011 |url-status=live  }}</ref> [[lightweight markup|lightweight]] [[wiki markup]] designed to be easier to use and learn than [[HTML]]. Tools exist for converting content such as [[Table (information)|tables]] between MediaWiki markup and HTML.<ref>{{cite web |url=https://tools.wmflabs.org/magnustools/html2wiki.php |title=HTML to Wiki Converter&nbsp;– tables |publisher=WMF Labs |date=March 29, 2008 |access-date=June 12, 2014 |archive-url=https://web.archive.org/web/20140713040132/https://tools.wmflabs.org/magnustools/html2wiki.php |archive-date=July 13, 2014 |url-status=live  }}</ref> 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.<ref>{{cite web |url=https://www.mediawiki.org/wiki/Markup_spec |title=Markup spec |publisher=MediaWiki |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20071219052149/https://www.mediawiki.org/wiki/Markup_spec |archive-date=December 19, 2007 |url-status=live  }}</ref><ref>{{cite web |url=https://www.cs.rmit.edu.au/adcs2010/proceedings/pdf/paper%204.pdf |title=Extricating Meaning from Wikimedia Article Archives |access-date=January 2, 2011 |archive-url=https://web.archive.org/web/20110310023318/https://www.cs.rmit.edu.au/adcs2010/proceedings/pdf/paper%204.pdf |archive-date=March 10, 2011 |url-status=live  }}</ref> The following side-by-side comparison illustrates the differences between wiki markup and HTML:

{| class="wikitable"
|-
! style="width:300px; height:94px; border-bottom-width:2px"|MediaWiki syntax <br /><span style="font-weight: normal; font-size: 98%">(the "behind the scenes" code<br /> used to add formatting to text)</span>
! style="width:376px; border-bottom-width:2px"|HTML equivalent <br /><span style="font-weight: normal; font-size: 98%">(another type of "behind the scenes" code<br /> used to add formatting to text)</span>
! style="width:230px; border-bottom-width:2px"|Rendered output <br /><span style="font-weight: normal; font-size: 98%">(seen onscreen by a site viewer)</span>
|- style="vertical-align:top;"
|<syntaxhighlight lang="wikitext">

====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."</syntaxhighlight>
|<syntaxhighlight lang="html">
<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> <br>
<p>"I've had nothing yet," Alice replied in an offended tone: "so I can't take more."</p> <br>
<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></syntaxhighlight>
|<div style="font-weight: bold; margin-top: 24px; margin-bottom: 16px">A dialogue</div>
"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."
|}
<small>(Quotation above from ''[[Alice's Adventures in Wonderland]]'' by [[Lewis Carroll]])</small>

===Editing interface===
{{see also|VisualEditor}}
[[File:MediaWiki 1.44.0-wmf.4 source editing at English Wikipedia screenshot.webp|thumb|upright=1.2|Editing interface of MediaWiki 1.44.0-wmf.4 with [[syntax highlighting]], showing the edit toolbar of 2017 wikitext editor and some examples of wiki syntax]]

MediaWiki's default page-editing tools have been described as somewhat challenging to learn.<ref>{{citation|publisher=Tech & Learning|url=https://www.techlearning.com/article/6164|title=Wild about Wikis|last=Jakes|first=David|date=August 15, 2006|access-date=April 23, 2010|archive-url=https://web.archive.org/web/20100502052101/https://www.techlearning.com/article/6164|archive-date=May 2, 2010|url-status=dead}}</ref> A survey of students assigned to use a MediaWiki-based wiki found that when they were asked an [[Open-ended question|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."<ref>{{citation|title=Wiki as a professional development tool|first1=Brian|last1=Foley|first2=Tae|last2=Chang|name-list-style=amp|year=2008|publisher=Technology and Teacher Education|url=https://www.csun.edu/~bfoley/AERA_Wiki.pdf|access-date=April 23, 2010|archive-url=https://web.archive.org/web/20110430024752/https://www.csun.edu/~bfoley/AERA_Wiki.pdf|archive-date=April 30, 2011|url-status=live}}</ref>

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]].

VisualEditor has its own integrated wikitext editing interface known as 2017 wikitext editor, the older editing interface is known as 2010 wikitext editor.

===Application programming interface===
MediaWiki has an extensible [[web API]] ([[application programming interface]]) that provides direct, high-level access to the data contained in the MediaWiki 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 [[Front and back ends|backend]] of another web site.<ref>{{cite web |url=https://www.mediawiki.org/wiki/API |title=API |publisher=MediaWiki |date=May 17, 2010 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20100527004158/https://www.mediawiki.org/wiki/API |archive-date=May 27, 2010 |url-status=live  }}</ref> An extensive [[Python (programming language)|Python]] [[Internet bot|bot]] library, [[Wikipedia:Pywikibot|Pywikibot]],<ref>{{cite web |url=https://www.mediawiki.org/wiki/Manual:Pywikibot |title=Pywikibot&nbsp;– MediaWiki |publisher=mediawiki.org |access-date=March 16, 2018 |archive-url=https://web.archive.org/web/20180309072418/https://www.mediawiki.org/wiki/Manual:Pywikibot |archive-date=March 9, 2018 |url-status=live  }}</ref> and a popular semi-automated tool called [[Wikipedia:AutoWikiBrowser|AutoWikiBrowser]], also interface with the API.<ref>{{cite web |author=Česky |url=https://en.wikipedia.org/wiki/Wikipedia:AutoWikiBrowser |title=Wikipedia:AutoWikiBrowser&nbsp;– Wikipedia, the free encyclopedia |publisher=En.wikipedia.org |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20100420235103/https://en.wikipedia.org/wiki/Wikipedia:AutoWikiBrowser |archive-date=April 20, 2010 |url-status=live  }}</ref> The API is accessed via URLs such as <code><nowiki>https://en.wikipedia.org/w/api.php?action=query&list=recentchanges</nowiki></code>. 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]].<ref>{{citation|title=Facilitating Wiki/Repository Communication with Metadata|url=https://smartech.gatech.edu/dspace/handle/1853/28426|author1=Bartolo, Laura M.|author2=Lowe, Cathy S.|author3=Songar, Poonam|author4=Tandy, Robert J.|date=May 20, 2009|publisher=Georgia Institute of Technology|access-date=April 23, 2010|archive-url=https://web.archive.org/web/20110109004041/https://smartech.gatech.edu/dspace/handle/1853/28426|archive-date=January 9, 2011|url-status=dead}}</ref> [[Client–server model|Client code]] has been developed to provide layers of [[abstraction (computer science)|abstraction]] to the API.<ref>{{cite web |url=https://www.mediawiki.org/wiki/API:Client_code |title=API:Client code |publisher=MediaWiki |date=May 24, 2010 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20100626072508/https://www.mediawiki.org/wiki/API:Client_code |archive-date=June 26, 2010 |url-status=live  }}</ref>

===Tracking edits===
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 [[Vandalism on Wikipedia|vandalism]]")<ref>{{cite web |url=https://en.wikipedia.org/wiki/Special:Tags |title=Tags&nbsp;– Wikipedia, the free encyclopedia |publisher=En.wikipedia.org |access-date=May 30, 2010 |archive-date=March 4, 2010 |archive-url=https://web.archive.org/web/20100304112922/https://en.wikipedia.org/wiki/Special:Tags |url-status=live }}</ref> added by customizable abuse filters and other extensions to aid in combating unhelpful edits.<ref>{{cite web |url=https://www.mediawiki.org/wiki/Manual:Tags |title=Manual:Tags |publisher=MediaWiki |date=August 31, 2009 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20100625224408/https://www.mediawiki.org/wiki/Manual:Tags |archive-date=June 25, 2010 |url-status=live  }}</ref> On more active wikis, so many edits occur that it is hard to track Recent Changes manually. Anti-vandal software, including user-assisted tools,<ref>{{cite web |url=https://en.wikipedia.org/wiki/Wikipedia:Huggle |title=Wikipedia:Huggle&nbsp;– Wikipedia, the free encyclopedia |publisher=En.wikipedia.org |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20110331172521/https://en.wikipedia.org/wiki/Wikipedia:Huggle |archive-date=March 31, 2011 |url-status=live  }}</ref> 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.<ref>{{cite web |url=https://meta.wikimedia.org/wiki/IRC/Channels#Raw_feeds |title=IRC/Channels |publisher=Meta-Wiki |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20100323020404/https://meta.wikimedia.org/wiki/IRC/Channels#Raw_feeds#Raw_feeds |archive-date=March 23, 2010 |url-status=live  }}</ref><ref>{{cite web| url= https://www.bbc.co.uk/news/magazine-18892510| title= Meet the 'bots' that edit Wikipedia| author= Daniel Nasaw| work= BBC News| date= July 25, 2012| access-date= July 30, 2012| archive-url= https://web.archive.org/web/20120728024625/https://www.bbc.co.uk/news/magazine-18892510| archive-date= July 28, 2012| url-status= live| df= mdy-all}}</ref>

Another important tool is watchlisting. 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.<ref>{{cite web |url=https://www.mediawiki.org/wiki/Manual:Watchlist |title=Manual:Watchlist |publisher=MediaWiki |date=November 24, 2009 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20110501081950/https://www.mediawiki.org/wiki/Manual:Watchlist |archive-date=May 1, 2011 |url-status=live  }}</ref> 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.<ref>{{citation|title=Wiki ware could harness the Internet for science|author=Kevin Yager|journal=Nature|date=March 16, 2006|volume=440|issue=7082|doi=10.1038/440278a|pages=278|pmid=16541049|bibcode=2006Natur.440..278Y|doi-access=free}}</ref>

===Navigation===

==== Wikilinks ====
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 those other articles being yet in existence.

==== Interwiki links ====
{{redirect|selfref=true|Inter-wiki link|help with interwiki linking on Wikipedia|Help:Interwiki linking}}
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 <code>wikiquote:Jimbo Wales</code> to direct the user to the Jimbo Wales article on [[Wikiquote]].<ref>{{cite web |url=https://www.mediawiki.org/wiki/Manual:Interwiki |title=Manual:Interwiki |publisher=MediaWiki |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20101203112631/https://www.mediawiki.org/wiki/Manual:Interwiki |archive-date=December 3, 2010 |url-status=live  }}</ref> Unlike internal wikilinks, interwiki links lack page existence detection functionality, and accordingly there is no way to tell whether a blue interwiki link is broken or not.

==== Interlanguage links ====
[[File:Interlanguage links prior to Wikidata.png|thumb|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.<ref>{{Cite web|title=Interlanguage links|url=https://www.mediawiki.org/wiki/Interlanguage_links|url-status=live|access-date=March 17, 2021|website=MediaWiki|language=en|archive-date=March 12, 2021|archive-url=https://web.archive.org/web/20210312133505/https://www.mediawiki.org/wiki/Interlanguage_links}}</ref>

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.<ref>{{Cite web|last=Pintscher|first=Lydia|date=September 23, 2013|title=Wikidata is Here!|url=https://commons.wikimedia.org/wiki/Commons:Village_pump/Archive/2013/10#Wikidata_is_here.21|url-status=live|access-date=March 17, 2021|website=[[Commons:Commons:Village pump|Commons:Village pump]]|language=en|archive-date=December 6, 2021|archive-url=https://web.archive.org/web/20211206060438/https://commons.wikimedia.org/wiki/Commons:Village_pump/Archive/2013/10#Wikidata_is_here.21}}</ref>

===Content organization===

====Page tabs and associated pages====
[[File:MediaWiki Vector skin tabs.png|frame|MediaWiki page tabs, using the "Vector 2010" skin. The red coloration of the "discussion" tab indicates that the article does not yet have a talk page. As with any other red wikilink, clicking on it prompts the user to create the page.]]
Page tabs are displayed at the top of pages. These tabs allow users to perform actions or view pages that are related to the current page. The available default actions include viewing, editing, and discussing the current page. The specific tabs displayed depend on whether the user is logged into the wiki and whether the user has sysop privileges on the wiki. For instance, the ability to move a page or add it to one's watchlist is usually restricted to logged-in users. The site administrator can add or remove tabs by using JavaScript or installing extensions.<ref>{{cite web |url=https://www.mediawiki.org/wiki/Help:Navigation#Page_Tabs |title=Help:Navigation |publisher=MediaWiki |date=May 21, 2010 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20100527004218/https://www.mediawiki.org/wiki/Help:Navigation#Page_Tabs#Page_Tabs |archive-date=May 27, 2010 |url-status=live  }}</ref>

Each page has an associated history page from which the user can access every version of the page that has ever existed and generate [[diff]]s between two versions of his choice. Users' contributions are displayed not only here, but also via a "user contributions" option on a sidebar. In a 2004 article, Carl Challborn and Teresa Reimann noted that "While this feature may be a slight deviation from the collaborative, 'ego-less' spirit of wiki purists, it can be very useful for educators who need to assess the contribution and participation of individual student users."<ref>{{citation|url=https://cde.athabascau.ca/softeval/reports/R470412.pdf|title=Wiki products: a comparison|author1=Carl Challborn|author2=Teresa Reimann|name-list-style=amp|date=December 2004|publisher=Athabasca University|access-date=April 23, 2010|archive-url=https://web.archive.org/web/20101223221302/https://cde.athabascau.ca/softeval/reports/R470412.pdf|archive-date=December 23, 2010|url-status=live}}</ref>

==== {{anchor|Talk page|Namespace}} Namespaces ====
{{redirect|selfref=true|Talk page|talk pages on Wikipedia|Help:Talk pages}}

MediaWiki provides many features beyond [[hyperlink]]s for structuring content. One of the earliest such features is ''[[namespace]]s''. One of Wikipedia's earliest problems had been the separation of encyclopedic content from pages pertaining to maintenance and communal discussion, as well as personal pages about encyclopedia editors. Namespaces are prefixes before a page title (such as "<code>User:</code>" or "<code>Talk:</code>") that serve as descriptors for the page's purpose and allow multiple pages with different functions to exist under the same title. For instance, a page titled "<code>{{brackets|The Terminator}}</code>", in the default namespace, could describe [[The Terminator|the 1984 movie]] starring [[Arnold Schwarzenegger]], while a page titled "<code>{{brackets|User:The Terminator}}</code>" could be a profile describing a user who chooses this name as a pseudonym. More commonly, each namespace has an associated "<code>Talk:</code>" namespace, which can be used to discuss its contents, such as "<code>User talk:</code>" or "<code>Template talk:</code>". The purpose of having discussion pages is to allow content to be separated from discussion surrounding the content.<ref>{{cite book |title=Enterprise 2. 0 Implementation |last1=Newman |first1=Aaron |first2=Adam |last2=Steinberg |first3=Jeremy |last3=Thomas |page=185 |publisher=McGraw-Hill Professional |year=2008 |isbn=978-0-07-159160-7}}</ref><ref>{{cite book |title=Multi-Stakeholder Governance and the Internet Governance Forum |url=https://archive.org/details/multistakeholder00malc |url-access=limited |author=Malcolm, Jeremy |pages=[https://archive.org/details/multistakeholder00malc/page/n216 188], 280 |publisher=Terminus Press |year=2008 |isbn=978-0-9805084-0-6}}</ref>

Namespaces can be viewed as [[file folder|folders]] that separate different basic types of information or functionality. Custom namespaces can be added by the site administrators. There are 16 namespaces by default for content, with 2 "pseudo-namespaces" used for dynamically generated "<code>Special:</code>" pages and links to media files. Each namespace on MediaWiki is numbered: content page namespaces have even numbers and their associated talk page namespaces have odd numbers.<ref>{{cite book|title=Wiki |url=https://archive.org/details/wikiwebcollabora00eber_531 |url-access=limited |last1=Ebersbach |first1=Anja |first2=Markus |last2=Glaser |first3=Richard |last3=Heigl |first4=Gunter |last4=Dueck |pages=[https://archive.org/details/wikiwebcollabora00eber_531/page/n68 55], 80–82, 109, 120–121, 156 |publisher=Springer |year=2006 |isbn=978-3-540-25995-4}}</ref>

====Category tags====
Users can create new categories and add pages and files to those categories by appending one or more category tags to the content text. Adding these tags creates links at the bottom of the page that take the reader to the list of all pages in that category, making it easy to browse related articles.<ref>{{cite web |url=https://www.mediawiki.org/wiki/Help:Categories |title=Help:Categories |publisher=MediaWiki |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20100625220958/https://www.mediawiki.org/wiki/Help:Categories |archive-date=June 25, 2010 |url-status=live  }}</ref> The use of categorization to organize content has been described as a combination of:
* [[Social bookmarking|Collaborative tagging systems]] like [[del.icio.us]] and
* [[Library classification|Hierarchical classifications]] like the [[Dewey Decimal Classification]].<ref>{{cite arXiv|title=Collaborative thesaurus tagging the Wikipedia way|eprint=cs.IR/0604036|date=April 27, 2006|author=Jakob Voss}}</ref>

====Subpages====
In addition to namespaces, content can be ordered using ''subpages''. This simple feature provides automatic [[breadcrumb (navigation)|breadcrumbs]] of the pattern <code>{{brackets|Page title/Subpage title}}</code> from the page after the slash (in this case, "Subpage title") to the page before the slash (in this case, "Page title").

===Customization===
[[File:Popup-preview.png|thumb|Users can configure custom [[JavaScript]] that is executed on every pageview. This has led to JavaScript tools that users can "install", the "navigation popups" tool shown here displays a small preview of an article when hovering over a link title.]]

If the feature is enabled, users can customize their stylesheets and configure [[client-side JavaScript]] to be executed with every pageview. On Wikipedia, this has led to a large number of additional tools and helpers developed through the wiki and shared among users. For instance, ''navigation popups'' is a custom JavaScript tool that shows previews of articles when the user hovers over links and also provides shortcuts for common maintenance tasks.<ref>{{cite web| url = https://en.wikipedia.org/wiki/Wikipedia:Tools/Navigation_popups| title = Wikipedia:Tools/Navigation popups| author = Lupin| archive-url = https://web.archive.org/web/20060718164504/https://en.wikipedia.org/wiki/Wikipedia%3ATools/Navigation_popups| archive-date = July 18, 2006| url-status = live| df = mdy-all}}</ref>

[[File:Screenshot-skin-material.png|thumb|A [[screenshot]] of a wiki using MediaWiki with a customized skin]]

The entire MediaWiki user interface can be edited through the wiki itself by users with the necessary permissions (typically called "administrators"). This is done through a special namespace with the prefix "MediaWiki:", where each page title identifies a particular user interface message. Using an extension,<ref>{{cite web |url=https://www.mediawiki.org/wiki/Extension:Gadgets |title=Extension:Gadgets |publisher=MediaWiki |date=March 30, 2010 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20100625220327/https://www.mediawiki.org/wiki/Extension:Gadgets |archive-date=June 25, 2010 |url-status=live  }}</ref> it is also possible for a user to create personal scripts, and to choose whether certain sitewide scripts should apply to them by toggling the appropriate options in the user preferences page.

===Templates===
The "MediaWiki:" namespace was originally also used for creating custom text blocks that could then be dynamically loaded into other pages using a special syntax. This content was later moved into its own namespace, "Template:".

Templates are text blocks that can be dynamically loaded inside another page whenever that page is requested. The template is a special link in double [[curly bracket]]s (for example "<code><nowiki>{{Disputed|date=October 2018}}</nowiki></code>"), which calls the template (in this case located at {{self-reference link|Template:Disputed}}) to load in place of the template call.

Templates are [[structured document]]s containing [[attribute–value pair]]s. They are defined with [[parameter]]s, to which are assigned [[Value (computer science)|values]] when [[transclusion|transcluded]] on an article page. The name of the parameter is [[Delimiter|delimited]] from the value by an [[equals sign]]. A class of templates known as [[infobox]]es is used on Wikipedia to collect and present a subset of information about its subject, usually on the top (mobile view) or top right-hand corner (desktop view) of the document.

Pages in other namespaces can also be transcluded as templates. In particular, a page in the main namespace can be transcluded by prefixing its title with a colon; for example, <code>{{((}}:MediaWiki{{))}}</code> transcludes the article "MediaWiki" from the main namespace. Also, it is possible to mark the portions of a page that should be transcluded in several ways, the most basic of which are:<ref>{{Cite conference |last=Anderson |first=Mark |last2=Carr |first2=Leslie |last3=Millard |first3=David E. |date=2017-07-04 |title=There and Here: Patterns of Content Transclusion in Wikipedia |url=https://dl.acm.org/doi/10.1145/3078714.3078726 |language=en |conference=28th ACM Conference on Hypertext and Social Media |location=Prague, Czech Republic |publisher=ACM |pages=115–124 |doi=10.1145/3078714.3078726 |isbn=978-1-4503-4708-2|url-access=subscription }}</ref>

* {{tag|noinclude}}, which marks content that is not to be transcluded;
* {{tag|includeonly}}, which marks content that is not rendered unless it is transcluded;
* {{tag|onlyinclude}}, which marks content that is to be the ''only'' content transcluded.

A related method, called template ''substitution'' (called by adding <code>subst:</code> at the beginning of a template link) inserts the contents of the template into the target page (like a [[copy and paste]] operation), instead of loading the template contents dynamically whenever the page is loaded. This can lead to inconsistency when using templates, but may be useful in certain cases, and in most cases requires fewer [[server (computing)|server]] resources (the actual amount of savings can vary depending on wiki configuration and the complexity of the template).

Templates have found many different uses. Templates enable users to create complex table layouts that are used consistently across multiple pages, and where only the content of the tables gets inserted using template parameters. Templates are frequently used to identify problems with a Wikipedia article by putting a template in the article. This template then outputs a graphical box stating that the article content is disputed or in need of some other attention, and also categorize it so that articles of this nature can be located. Templates are also used on user pages to send users standard messages welcoming them to the site,<ref>{{cite web |author=Česky |url=https://en.wikipedia.org/wiki/Template:Welcome |title=Template:Welcome&nbsp;– Wikipedia, the free encyclopedia |publisher=En.wikipedia.org |date=May 16, 2010 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20110506003930/https://en.wikipedia.org/wiki/Template:Welcome |archive-date=May 6, 2011 |url-status=live  }}</ref> giving them awards for outstanding contributions,<ref>{{citation|url=https://portal.acm.org/citation.cfm?id=1460563.1460573|publisher=Proceedings of the ACM|author1=T Kriplean |author2=I Beschastnikh | title=Proceedings of the 2008 ACM conference on Computer supported cooperative work | chapter=Articulations of wikiwork: Uncovering valued work in wikipedia through barnstars |year=2008|pages = 47–56|doi = 10.1145/1460563.1460573|isbn = 9781605580074|s2cid = 7164949|display-authors=etal|url-access=subscription}}</ref><ref>{{cite web |author=Česky |url=https://en.wikipedia.org/wiki/Wikipedia:Barnstars |title=Wikipedia:Barnstars&nbsp;– Wikipedia, the free encyclopedia |publisher=En.wikipedia.org |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20090624134612/https://en.wikipedia.org/wiki/Wikipedia:Barnstars |archive-date=June 24, 2009 |url-status=live  }}</ref> warning them when their behavior is considered inappropriate,<ref>{{cite web |author=Česky |url=https://en.wikipedia.org/wiki/Template:Test |title=Template:Test&nbsp;– Wikipedia, the free encyclopedia |publisher=En.wikipedia.org |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20091111014442/https://en.wikipedia.org/wiki/Template:Test |archive-date=November 11, 2009 |url-status=live  }}</ref> notifying them when they are blocked from editing,<ref>{{cite web |url=https://en.wikipedia.org/wiki/Template:Test5 |title=Template:Test5&nbsp;– Wikipedia, the free encyclopedia |publisher=En.wikipedia.org |date=June 19, 2008 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20090424005115/https://en.wikipedia.org/wiki/Template:Test5 |archive-date=April 24, 2009 |url-status=live  }}</ref> and so on.

===Groups and restriction of access===
MediaWiki offers flexibility in creating and defining user groups. For instance, it would be possible to create an arbitrary "ninja" group that can block users and delete pages, and whose edits are hidden by default in the recent changes log. It is also possible to set up a group of "autoconfirmed" users that one becomes a member of after making a certain number of edits and waiting a certain number of days.<ref>{{cite web |url=https://www.mediawiki.org/wiki/Manual:User_rights_management#Automatically_promote_users |title=Manual:User rights management |publisher=MediaWiki |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20100625222112/https://www.mediawiki.org/wiki/Manual%3AUser_rights_management#Automatically_promote_users#Automatically_promote_users |archive-date=June 25, 2010 |url-status=live  }}</ref> Some groups that are enabled by default are bureaucrats and sysops. Bureaucrats have the power to change other users' rights. Sysops have power over page protection and [[Deletion of articles on Wikipedia|deletion]] and the blocking of users from editing. MediaWiki's available controls on editing rights have been deemed sufficient for publishing and maintaining important documents such as a manual of [[standard operating procedures]] in a hospital.<ref>{{citation|title=Operating Procedures in Clinical Practice|author1=H Zielke|author2=W Boemke|author3=M Kastrup|author4=C Melzer|publisher=Royal College of Anaesthetists|url=https://www.scata.org.uk/abstracts/2007_london/DelegateBookletSCATALondon2007.pdf|date=November 21, 2007|access-date=April 25, 2010|archive-url=https://web.archive.org/web/20110515020030/https://www.scata.org.uk/abstracts/2007_london/DelegateBookletSCATALondon2007.pdf|archive-date=May 15, 2011|url-status=live}}</ref>

MediaWiki comes with a basic set of features related to restricting access, but its original and ongoing design is driven by functions that largely relate to content, not content segregation. As a result, with minimal exceptions (related to specific tools and their related "Special" pages), page access control has never been a high priority in core development and developers have stated that users requiring secure user access and authorization controls should not rely on MediaWiki, since it was never designed for these kinds of situations. For instance, it is extremely difficult to create a wiki where only certain users can read and access some pages.<ref>{{cite web |url=https://www.mediawiki.org/wiki/Security_issues_with_authorization_extensions |title=Security issues with authorization extensions |publisher=MediaWiki |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20100626074354/https://www.mediawiki.org/wiki/Security_issues_with_authorization_extensions |archive-date=June 26, 2010 |url-status=live  }}</ref> Here, wiki engines like [[Foswiki]], [[MoinMoin]] and [[Confluence (software)|Confluence]] provide more flexibility by supporting advanced security mechanisms like [[access control list]]s.

===Extensibility===
The MediaWiki codebase contains various [[Hooking|hooks]] using [[callback (computer science)|callback]] [[Subroutine|functions]] to add additional PHP code in an [[Extensibility|extensible]] way. This allows developers to write extensions without necessarily needing to modify the core or having to submit their code for review. Installing an extension typically consists of adding a line to the configuration file, though in some cases additional changes such as database updates or core patches are required.

Five main extension points were created to allow developers to add features and functionalities to MediaWiki. Hooks are run every time a certain event happens; for instance, the <code>ArticleSaveComplete</code> hook occurs after a save article request has been processed.<ref>{{cite web |url=https://www.mediawiki.org/wiki/Manual:Hooks/ArticleSaveComplete |title=Manual:Hooks/ArticleSaveComplete |publisher=MediaWiki |date=May 26, 2010 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20141110145905/https://www.mediawiki.org/wiki/Manual:Hooks/ArticleSaveComplete |archive-date=November 10, 2014 |url-status=live  }}</ref> This can be used, for example, by an extension that notifies selected users whenever a page edit occurs on the wiki from new or anonymous users.<ref>{{cite web |url=https://www.mediawiki.org/wiki/Extension:Recent_Activity_Notify |title=Extension:Recent Activity Notify |publisher=MediaWiki |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20140927110023/https://www.mediawiki.org/wiki/Extension:Recent_Activity_Notify |archive-date=September 27, 2014 |url-status=live  }}</ref> New tags can be created to process data with opening and closing tags (<code><newtag>...</newtag></code>).<ref>{{cite web |url=https://www.mediawiki.org/wiki/Manual:Tag_extensions |title=Manual:Tag extensions |publisher=MediaWiki |date=May 21, 2010 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20141012211540/https://www.mediawiki.org/wiki/Manual:Tag_extensions |archive-date=October 12, 2014 |url-status=live  }}</ref> Parser functions can be used to create a new command (<code><nowiki>{{#if:...|...|...}}</nowiki></code>).<ref>{{cite web |url=https://www.mediawiki.org/wiki/Manual:Parser_functions |title=Manual:Parser functions |publisher=MediaWiki |date=March 22, 2010 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20141018103626/https://www.mediawiki.org/wiki/Manual:Parser_functions |archive-date=October 18, 2014 |url-status=live  }}</ref> New special pages can be created to perform a specific function. These pages are dynamically generated. For example, a special page might show all pages that have one or more links to an external site or it might create a form providing user submitted feedback.<ref>{{cite web |url=https://www.mediawiki.org/wiki/Manual:Special_pages |title=Manual:Special pages |publisher=MediaWiki |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20141110162401/https://www.mediawiki.org/wiki/Manual:Special_pages |archive-date=November 10, 2014 |url-status=live  }}</ref> [[Skin (computing)|Skins]] allow users to customize the look and feel of MediaWiki.<ref>{{cite web |url=https://www.mediawiki.org/wiki/Skin |title=Manual:Skins |publisher=MediaWiki |date=May 14, 2010 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20141125085917/https://www.mediawiki.org/wiki/Skin |archive-date=November 25, 2014 |url-status=live  }}</ref> A minor extension point allows the use of [[Amazon S3]] to host image files.<ref>{{cite web |url=https://www.mediawiki.org/wiki/Manual:Integration_with_S3 |title=Manual:Integration with S3 |publisher=MediaWiki |date=March 22, 2010 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20141127084520/https://www.mediawiki.org/wiki/Manual:Integration_with_S3 |archive-date=November 27, 2014 |url-status=live  }}</ref>

==Extensions==
===Text manipulation===
[[File:Tim Starling June08.jpg|thumb|Tim Starling in 2008]]
Among the most popular extensions is a parser function extension, ParserFunctions, which allows different content to be rendered based on the result of [[Conditional (programming)|conditional statements]].<ref>{{cite web |url=https://www.mediawiki.org/wiki/Extension:ParserFunctions |title=Extension:ParserFunctions |publisher=MediaWiki |date=December 25, 2009 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20100625222930/https://www.mediawiki.org/wiki/Extension%3AParserFunctions |archive-date=June 25, 2010 |url-status=live  }}</ref> These conditional statements can perform functions such as evaluating whether a parameter is empty, comparing strings, evaluating mathematical expressions, and returning one of two values depending on whether a page exists. It was designed as a replacement for a notoriously inefficient template called <nowiki>{{Qif}}</nowiki>.<ref>{{cite web |url=https://en.wikipedia.org/wiki/Wikipedia:Miscellany_for_deletion/Template:Qif |title=Wikipedia:Miscellany for deletion/Template:Qif&nbsp;– Wikipedia, the free encyclopedia |publisher=En.wikipedia.org |access-date=May 30, 2010 |archive-date=February 25, 2015 |archive-url=https://web.archive.org/web/20150225125827/https://en.wikipedia.org/wiki/Wikipedia:Miscellany_for_deletion/Template:Qif |url-status=live }}</ref> Schindler recounts the history of the ParserFunctions extension as follows:<ref name=Introducing/>
{{cquote|In 2006 some Wikipedians discovered that through an intricate and complicated interplay of templating features and CSS they could create conditional wiki text, i.e. text that was displayed if a template parameter had a specific value. This included repeated calls of templates within templates, which bogged down the performance of the whole system. The developers faced the choice of either disallowing the spreading of an obviously desired feature by detecting such usage and explicitly disallowing it within the software or offering an efficient alternative. The latter was done by Tim Starling, who announced the introduction of parser functions, wiki text that calls functions implemented in the underlying software.

At first, only conditional text and the computation of simple mathematical expressions were implemented, but this already increased the possibilities for wiki editors enormously. With time further parser functions were introduced, finally leading to a framework that allowed the simple writing of extension functions to add arbitrary functionalities, like e.g. geo-coding services or widgets. This time the developers were clearly reacting to the demand of the community, being forced either to fight the solution of the issue that the community had (i.e. conditional text), or offer an improved technical implementation to replace the previous practice and achieve an overall better performance.}}

Another parser functions extension, StringFunctions, was developed to allow evaluation of string length, string position, and so on. Wikimedia communities, having created awkward workarounds to accomplish the same functionality,<ref>{{cite web |url=https://en.wikipedia.org/wiki/Category:String_manipulation_templates |title=Category:String manipulation templates&nbsp;– Wikipedia, the free encyclopedia |publisher=En.wikipedia.org |date=May 15, 2010 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20110506003940/https://en.wikipedia.org/wiki/Category:String_manipulation_templates |archive-date=May 6, 2011 |url-status=live  }}</ref> clamored for it to be enabled on their projects.<ref>{{cite web |url=https://bugzilla.wikimedia.org/show_bug.cgi?id=6455 |title=Bug 6455 – Enable StringFunctions on WMF wikis |publisher=bugzilla.wikimedia.org |access-date=October 9, 2010 |archive-date=January 22, 2012 |archive-url=https://web.archive.org/web/20120122061250/https://bugzilla.wikimedia.org/show_bug.cgi?id=6455 |url-status=live }}</ref> Much of its functionality was eventually integrated into the ParserFunctions extension,<ref>{{cite web |url=https://www.mediawiki.org/wiki/Extension:StringFunctions |title=Extension:StringFunctions |publisher=MediaWiki |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20100625221030/https://www.mediawiki.org/wiki/Extension:StringFunctions |archive-date=June 25, 2010 |url-status=live  }}</ref> albeit disabled by default and accompanied by a warning from Tim Starling that enabling string functions would allow users "to implement their own parsers in the ugliest, most inefficient programming language known to man: MediaWiki wikitext with ParserFunctions."<ref>{{cite web |url=https://www.mediawiki.org/wiki/Special:Code/MediaWiki/51497 |title=r51497&nbsp;– Code Review |publisher=MediaWiki |access-date=May 30, 2010 |archive-date=November 27, 2014 |archive-url=https://web.archive.org/web/20141127205157/https://www.mediawiki.org/wiki/Special:Code/MediaWiki/51497 |url-status=live }}</ref>

=== Lua extension ===
Since 2012 an extension, Scribunto, has existed that allows for the creation of "modules"—wiki pages written in the scripting language [[Lua (programming language)|Lua]]—which can then be run within templates and standard wiki pages. Scribunto has been installed on Wikipedia and other Wikimedia sites since 2013 and is used heavily on those sites. Scribunto code runs significantly faster than corresponding wikitext code using ParserFunctions.<ref>{{Cite web |url=https://en.wikipedia.org/wiki/User:Dragons_flight/Lua_performance |title=Lua performance |access-date=December 27, 2018 |archive-date=August 24, 2018 |archive-url=https://web.archive.org/web/20180824045534/https://en.wikipedia.org/wiki/User:Dragons_flight/Lua_performance |url-status=live }}</ref>

===For footnotes and academic-related display===
Another very popular extension is a citation extension that enables footnotes to be added to pages using inline references.<ref>{{cite web |url=https://www.mediawiki.org/wiki/Extension:Cite |title=Extension:Cite |publisher=MediaWiki |date=May 3, 2010 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20141020220333/https://www.mediawiki.org/wiki/Extension:Cite |archive-date=October 20, 2014 |url-status=live  }}</ref> This extension has, however, been criticized for being difficult to use and requiring the user to memorize complex syntax. A gadget called [[Wikipedia:RefToolbar|RefToolbar]] attempts to make it easier to create citations using common templates. MediaWiki has some extensions that are well-suited for academia, such as mathematics extensions<ref>{{cite web |url=https://www.mediawiki.org/wiki/Category:Math_extensions |title=Category:Math extensions |publisher=MediaWiki |date=December 26, 2009 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20110501083222/https://www.mediawiki.org/wiki/Category:Math_extensions |archive-date=May 1, 2011 |url-status=live  }}</ref> and an extension that allows molecules to be rendered in [[Three-dimensional space|3D]].<ref name="Wikido">{{citation|title=Wikido: Exploiting the Potential of Wikis|issue=50|date=January 2007|author=Marieke Guy|publisher=Ariadne|url=https://www.ariadne.ac.uk/issue50/wikido-rpt/|access-date=April 23, 2010|archive-url=https://web.archive.org/web/20100407170018/https://www.ariadne.ac.uk/issue50/wikido-rpt/|archive-date=April 7, 2010|url-status=live}}</ref>

===Integration===
A generic Widgets extension exists that allows MediaWiki to integrate with virtually anything. Other examples of extensions that could improve a wiki are category suggestion extensions<ref>{{cite web |url=https://www.mediawiki.org/wiki/Extension:CategorySuggest |title=Extension:CategorySuggest |publisher=MediaWiki |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20140926005855/https://www.mediawiki.org/wiki/Extension:CategorySuggest |archive-date=September 26, 2014 |url-status=live  }}</ref> and extensions for inclusion of [[Flash Video]]s,<ref>{{cite web |url=https://www.mediawiki.org/wiki/Category:Flash_Video_extensions |title=Category:Flash Video extensions |publisher=MediaWiki |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20140915080226/https://www.mediawiki.org/wiki/Category:Flash_Video_extensions |archive-date=September 15, 2014 |url-status=live  }}</ref> YouTube videos,<ref>{{cite web |url=https://www.mediawiki.org/wiki/Category:YouTube_extensions |title=Category:YouTube extensions |publisher=MediaWiki |date=September 16, 2008 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20110501083939/https://www.mediawiki.org/wiki/Category:YouTube_extensions |archive-date=May 1, 2011 |url-status=live  }}</ref> and [[RSS feed]]s.<ref>{{cite web |url=https://www.mediawiki.org/wiki/Category:RSS_extensions |title=Category:RSS extensions |publisher=MediaWiki |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20101203095104/https://www.mediawiki.org/wiki/Category:RSS_extensions |archive-date=December 3, 2010 |url-status=live  }}</ref> [[Metavid]], a site that archives video footage of the [[U.S. Senate]] and [[U.S. House|House]] floor proceedings, was created using code extending MediaWiki into the domain of collaborative video authoring.<ref>{{citation|title=System demonstration: Metavid.org: a social website and open archive of congressional video|url=https://portal.acm.org/citation.cfm?id=1556176.1556232|publisher=Proceedings of the 10th Annual International Conference on Digital Government Research: Social Networks: Making Connections between Citizens, Data and Government|pages=309–310|isbn=978-1-60558-535-2|author1=M Dale |author2=A Stern |author3=M Deckert |author4=W Sack |year = 2009}}</ref>

===Combating linkspam===
There are many [[spambot]]s that search the web for MediaWiki installations and add [[spamdexing|linkspam]] to them, despite the fact that MediaWiki uses the [[nofollow]] attribute to discourage such attempts at [[search engine optimization]].<ref>{{cite web |url=https://meta.wikimedia.org/wiki/Wiki_Spam |title=Wiki spam |publisher=Meta-Wiki |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20141107131454/https://meta.wikimedia.org/wiki/Wiki_Spam |archive-date=November 7, 2014 |url-status=live  }}</ref> Part of the problem is that third party republishers, such as [[mirror website|mirrors]], may not independently implement the nofollow tag on their websites, so marketers can still get [[PageRank]] benefit by inserting links into pages when those entries appear on third party websites.<ref>{{citation|title=Wikipedia's Labor Squeeze and its Consequences|publisher=Journal on Telecommunications and High Technology Law|author=Goldman, Eric|volume=8}}</ref> [[Anti-spam]] extensions have been developed to combat the problem by introducing [[CAPTCHA]]s,<ref>{{cite web |url=https://www.mediawiki.org/wiki/Extension:ConfirmEdit |title=Extension:ConfirmEdit |publisher=MediaWiki |date=May 5, 2010 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20141020204041/https://www.mediawiki.org/wiki/Extension:ConfirmEdit |archive-date=October 20, 2014 |url-status=live  }}</ref> [[blacklist]]ing certain URLs,<ref>{{cite web |url=https://www.mediawiki.org/wiki/Extension:SpamBlacklist |title=Extension:SpamBlacklist |publisher=MediaWiki |date=March 24, 2010 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20141020220337/https://www.mediawiki.org/wiki/Extension:SpamBlacklist |archive-date=October 20, 2014 |url-status=live  }}</ref> and allowing bulk deletion of pages recently added by a particular user.<ref>{{cite web |url=https://www.mediawiki.org/wiki/Extension:Nuke |title=Extension:Nuke |publisher=MediaWiki |date=May 19, 2010 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20141020204031/https://www.mediawiki.org/wiki/Extension:Nuke |archive-date=October 20, 2014 |url-status=live  }}</ref>

===Searches and queries===
[[File:Autocompletion suggester after - airiana grande.gif|thumb|A search box showing a [[search suggest drop-down list|drop-down list]]]]
MediaWiki comes pre-installed with a standard text-based search. Extensions exist to let MediaWiki use more sophisticated third-party search engines, including [[Elasticsearch]] (which since 2014 has been in use on Wikipedia), [[Lucene]]<ref>[https://www.mediawiki.org/wiki/Extension:Lucene-search Lucene-search MediaWiki extension] {{Webarchive|url=https://web.archive.org/web/20120602042925/https://www.mediawiki.org/wiki/Extension:Lucene-search |date=June 2, 2012 }}, mediawiki.org</ref> and [[Sphinx (search engine)|Sphinx]].<ref>[https://www.mediawiki.org/wiki/Extension:SphinxSearch SphinxSearch MediaWiki extension] {{Webarchive|url=https://web.archive.org/web/20141022092204/https://www.mediawiki.org/wiki/Extension:SphinxSearch |date=October 22, 2014 }}, mediawiki.org</ref>

Various MediaWiki extensions have also been created to allow for more complex, [[faceted search]], on both data entered within the wiki and on [[metadata]] such as pages' revision history.<ref>{{citation|title=Search extension transforms Wiki into a relational system: A case for flavonoid metabolite database|pmc=2556319|author1=Masanori Arita  |author2=Kazuhiro Suwa |name-list-style=amp |date=September 17, 2008|publisher=BioData Mining |pmid=18822113 |doi=10.1186/1756-0381-1-7 |volume=1 |issue=1|journal=BioData Min |pages=7 |doi-access=free }}</ref><ref name="Lost in localization">{{Cite Q | Q21011200 }}</ref> [[Semantic MediaWiki]] is one such extension.<ref>{{citation|title=Collaborative Authoring of Learning Elements for Adaptive Learning Spaces|author1=Eric Ras|author2=Jörg Rech|author3=Sebastian Weber|publisher=Fifth International Conference on Adaptive Hypermedia and Adaptive Web-Based Systems|date=August 1, 2008|url=https://ah2008.l3s.uni-hannover.de/files/resourcesmodule/@random4875cb58f07c9/1215679368__Proc_AH2008_WS3_Authoring_of_Adaptive_and_Adaptable_Hypermedia.pdf#page=67|access-date=April 23, 2010|archive-url=https://web.archive.org/web/20110503215922/https://ah2008.l3s.uni-hannover.de/files/resourcesmodule/@random4875cb58f07c9/1215679368__Proc_AH2008_WS3_Authoring_of_Adaptive_and_Adaptable_Hypermedia.pdf#page=67#page=67|archive-date=May 3, 2011|url-status=live}}</ref><ref>{{cite book|page=123|chapter=A Platform for Collaborative Management of Semantic Grid Metadata|last=Hartung|first=Michael|title=Intelligent distributed computing, systems and applications|display-authors=etal}}</ref>

===Rich content===
[[File:MediaWiki's gallery feature.png|thumb|[[Image]]s can be arranged in galleries, a feature that is used extensively for Wikimedia's media archive, [[Wikimedia Commons]].]]

Various extensions to MediaWiki support [[rich media|rich content]] generated through specialized syntax. These include mathematical formulas using [[LaTeX]], graphical timelines over mathematical [[Plot (graphics)|plotting]], [[Sheet music|musical scores]] and [[Egyptian hieroglyphs]].

The software supports a wide variety of uploaded media files, and allows image galleries and thumbnails to be generated with relative ease. There is also support for [[Exif]] [[metadata]]. MediaWiki operates the [[Wikimedia Commons]], one of the largest [[free content]] media archives.

For WYSIWYG editing, [[VisualEditor]] is available to use in MediaWiki which simplifying editing process for editors and has been bundled since MediaWiki 1.35.<ref>{{Cite web|title=Extension:VisualEditor|url=https://www.mediawiki.org/wiki/Extension:VisualEditor|url-status=live|access-date=March 15, 2021|website=MediaWiki|language=en|archive-date=February 21, 2021|archive-url=https://web.archive.org/web/20210221063745/https://www.mediawiki.org/wiki/Extension:VisualEditor}}</ref> Other extensions exist for handling WYSIWYG editing to different degrees.<ref>{{cite web |url=https://www.mediawiki.org/wiki/Category:WYSIWYG_extensions |title=Category:WYSIWYG extensions |publisher=MediaWiki |date=April 10, 2008 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20110501083632/https://www.mediawiki.org/wiki/Category:WYSIWYG_extensions |archive-date=May 1, 2011 |url-status=live  }}</ref>

==Database==
[[File:MediaWiki database schema latest.svg|thumb|A schematic of the MediaWiki database structure]]

MediaWiki can use either the [[MySQL]]/[[MariaDB]], [[PostgreSQL]] or [[SQLite]] [[relational database management system]]. Support for [[Oracle Database]] and [[Microsoft SQL Server]] has been dropped since MediaWiki 1.34.<ref>{{Cite web|title=Manual:Installation requirements|url=https://www.mediawiki.org/wiki/Manual:Installation_requirements|url-status=live|access-date=March 14, 2021|website=MediaWiki|language=en|archive-date=March 8, 2021|archive-url=https://web.archive.org/web/20210308104956/https://www.mediawiki.org/wiki/Manual:Installation_requirements}}</ref> A MediaWiki database contains several dozen [[table (database)|tables]], including a <code>page</code> table that contains page titles, page ids, and other metadata;<ref>{{cite web |url=https://www.mediawiki.org/wiki/Manual:Page_table |title=Manual:Page table |publisher=MediaWiki |date=May 15, 2010 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20141125051102/https://www.mediawiki.org/wiki/Manual:Page_table |archive-date=November 25, 2014 |url-status=live  }}</ref> and a <code>revision</code> table to which is added a new row every time an edit is made, containing the page id, a brief textual summary of the change performed, the user name of the article editor (or its IP address the case of an unregistered user) and a timestamp.<ref>{{cite web |url=https://www.mediawiki.org/wiki/Manual:Revision_table |title=Manual:Revision table |publisher=MediaWiki |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20141124224756/https://www.mediawiki.org/wiki/Manual:Revision_table |archive-date=November 24, 2014 |url-status=live  }}</ref><ref>{{citation|title=The Top-Ten Wikipedias: A Quantitative Analysis Using WikiXRay|author1=Ortega, Felipe |author2=González-Barahona, Jesus M. |author3=Robles, Gregorio |year=2007|citeseerx=10.1.1.107.1424 }}</ref>

In a 4½ year period prior to 2008, the MediaWiki database had 170 [[database schema|schema]] versions.<ref>{{citation|title=Information Systems Integration and Evolution: Ontologies at Rescue|url=https://yellowstone.cs.ucla.edu/schema-evolution/documents/curino-STSM08-CR.pdf|author1=Curino, Carlo A.|author2=Tanca, Letizia|author3=Zaniolo, Carlo|year=2008|publisher=Workshop on Semantic|access-date=April 23, 2010|archive-url=https://web.archive.org/web/20091222052156/https://yellowstone.cs.ucla.edu/schema-evolution/documents/curino-STSM08-CR.pdf|archive-date=December 22, 2009|url-status=live}}</ref> Possibly the largest schema change was done in 2005 with MediaWiki 1.5, when the storage of metadata was separated from that of content, to improve performance flexibility. When this upgrade was applied to Wikipedia, the site was locked for editing, and the schema was converted to the new version in about 22 hours. Some software enhancement proposals, such as a proposal to allow sections of articles to be watched via watchlist, have been rejected because the necessary schema changes would have required excessive Wikipedia downtime.<ref>{{citation|title=No downtime for data conversions: Rethinking hot upgrades|url=https://www.pdl.cmu.edu/PDL-FTP/stray/CMU-PDL-09-106.pdf|author1=T Dumitras|author2=P Narasimhan|year=2009|access-date=April 29, 2010|archive-url=https://web.archive.org/web/20100616022532/https://www.pdl.cmu.edu/PDL-FTP/stray/CMU-PDL-09-106.pdf|archive-date=June 16, 2010|url-status=dead}}</ref>

==Performance and storage==
Because it is used to run one of the highest-traffic sites on the Web, Wikipedia, MediaWiki's performance and [[scalability]] have been highly optimized.<ref name="WikipediaandMediaWikiTalk"/> MediaWiki supports [[Squid (software)|Squid]], [[load balancing (computing)|load-balanced]] database replication, client-side caching, [[memcached]] or table-based caching for frequently accessed processing of query results, a simple static file cache, feature-reduced operation, revision compression, and a job queue for database operations. MediaWiki developers have attempted to optimize the software by avoiding expensive algorithms, database queries, etc., caching every result that is expensive and has temporal locality of reference, and focusing on the hot spots in the code through [[Profiling (computer programming)|profiling]].<ref name="Bergsma">{{citation|author=Bergsma, Mark|url=https://www.haute-disponibilite.net/wp-content/uploads/2008/06/wikimedia-architecture.pdf|title=Wikimedia Architecture|access-date=October 21, 2015|archive-url=https://web.archive.org/web/20160305000935/https://www.haute-disponibilite.net/wp-content/uploads/2008/06/wikimedia-architecture.pdf|archive-date=March 5, 2016|url-status=live}}</ref>

MediaWiki code is designed to allow for data to be written to a read-write database and read from read-only databases, although the read-write database can be used for some read operations if the read-only databases are not yet up to date. [[Metadata]], such as article revision history, article relations (links, categories etc.), user accounts and settings can be stored in core databases and cached; the actual revision text, being more rarely used, can be stored as append-only [[Blob storage|blobs]] in external storage.  The software is suitable for the operation of large-scale [[wiki farm]]s such as [[Wikimedia]], which had about 800 wikis as of August 2011. However, MediaWiki comes with no built-in GUI to manage such installations.

Empirical evidence shows most revisions in MediaWiki databases tend to differ only slightly from previous revisions. Therefore, subsequent revisions of an article can be concatenated and then compressed, achieving very high [[data compression ratio]]s of up to 100×.<ref name=Bergsma />

For more information on the architecture, such as how it stores wikitext and assembles a page, see [[#External links|''External links'']].

==Limitations==
The parser serves as the ''de facto'' standard for the MediaWiki syntax, as no formal syntax has been defined. Due to this lack of a formal definition, it has been difficult to create [[WYSIWYG]] editors for MediaWiki, although several WYSIWYG extensions do exist, including the popular [[VisualEditor]].

MediaWiki is not designed to be a suitable replacement for dedicated [[online forum]] or blogging software,<ref>{{cite web |url=https://www.mediawiki.org/wiki/Manual:What_is_MediaWiki%3F |title=Manual:What is |publisher=MediaWiki |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20180722205421/https://www.mediawiki.org/wiki/Manual:What_is_MediaWiki%3F |archive-date=July 22, 2018 |url-status=live  }}</ref> although extensions do exist to allow for both of these.<ref>{{cite web |url=https://www.mediawiki.org/wiki/Extension:StructuredDiscussions |title=Extension:StructuredDiscussions |publisher=MediaWiki |access-date=December 27, 2018 |archive-date=December 27, 2018 |archive-url=https://web.archive.org/web/20181227181448/https://www.mediawiki.org/wiki/Extension:StructuredDiscussions |url-status=live }}</ref><ref>{{cite web |url=https://www.mediawiki.org/wiki/Extension:Wikilog |title=Extension:Wikilog |publisher=MediaWiki |date=November 27, 2009 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20140922080626/https://www.mediawiki.org/wiki/Extension:Wikilog |archive-date=September 22, 2014 |url-status=live  }}</ref>

It is common for new MediaWiki users to make certain mistakes, such as forgetting to sign posts with four tildes (<nowiki>~~~~</nowiki>),<ref>{{cite web |url=https://www.mediawiki.org/wiki/Help:Signatures |title=Help:Signatures |publisher=MediaWiki |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20081115143342/https://www.mediawiki.org/wiki/Help:Signatures |archive-date=November 15, 2008 |url-status=live  }}</ref> or manually entering a plaintext signature,<ref>{{citation|citeseerx = 10.1.1.133.1456|author1=N Augar |author2=R Raitman |author3=W Zhou |title=Teaching and learning online with wikis|publisher=Beyond the comfort zone|year=2004|pages=95–104 }}</ref> due to unfamiliarity with the idiosyncratic particulars involved in communication on MediaWiki discussion pages. On the other hand, the format of these discussion pages has been cited as a strength by one educator, who stated that it provides more fine-grain capabilities for discussion than traditional threaded discussion forums. For example, instead of 'replying' to an entire message, the participant in a discussion can create a hyperlink to a new wiki page on any word from the original page. Discussions are easier to follow since the content is available via hyperlinked wiki page, rather than a series of reply messages on a traditional threaded discussion forum. However, except in few cases, students were not using this capability, possibly because of their familiarity with the traditional linear discussion style and a lack of guidance on how to make the content more '[[link-rich]]'.<ref>{{citation|title=Analysis of the use of Wiki-based collaborations in enhancing student learning|author=Cubric, Marija|publisher=University of Hertfordshire|year=2007|page=11|url=https://uhra.herts.ac.uk/dspace/handle/2299/3672|access-date=April 24, 2010|archive-url=https://web.archive.org/web/20110515005430/https://uhra.herts.ac.uk/dspace/handle/2299/3672|archive-date=May 15, 2011|url-status=dead}}</ref>

MediaWiki by default has little support for the creation of dynamically assembled documents, or pages that aggregate data from other pages. Some research has been done on enabling such features directly within MediaWiki.<ref>{{citation|title=User defined structural searches in mediawiki|url=https://portal.acm.org/citation.cfm?id=1379099|publisher=Proceedings of the nineteenth ACM conference on Hypertext and hypermedia|isbn=978-1-59593-985-2|year=2008|author1=Albertsen, Johannes  |author2=Bouvin, Niels Olof |name-list-style=amp }}</ref> The [[Semantic MediaWiki]] extension provides these features. It is not in use on Wikipedia, but in more than 1,600 other MediaWiki installations.<ref>{{Cite web |url=https://wikiapiary.com/wiki/Extension:Semantic_MediaWiki |title=Extension:Semantic MediaWiki – WikiApiary |access-date=October 12, 2019 |archive-date=October 26, 2018 |archive-url=https://web.archive.org/web/20181026002750/https://wikiapiary.com/wiki/Extension:Semantic_Mediawiki |url-status=live }}</ref> The Wikibase Repository and Wikibase Repository client are however implemented in [[Wikidata]] and [[Wikipedia]] respectively, and to some extent provides [[semantic web]] features, and linking of centrally stored data to infoboxes in various Wikipedia articles.

Upgrading MediaWiki is usually fully automated, requiring no changes to the site content or template programming. Historically troubles have been encountered when upgrading from significantly older versions.<ref>{{citation|title=Toward upgrades-as-a-service in distributed systems|author1=T Dumitraş |author2=P Narasimhan |publisher=Proceedings of the 10th ACM/IFIP/USENIX International Conference on Middleware|year=2009|pages=1–2 |url=https://portal.acm.org/citation.cfm?id=1657019}}</ref>

==Security==
MediaWiki developers have enacted security standards, both for core code and extensions.<ref>{{cite web |url=https://www.mediawiki.org/wiki/Security_for_developers |title=Security for developers |publisher=MediaWiki |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20141125053458/https://www.mediawiki.org/wiki/Security_for_developers |archive-date=November 25, 2014 |url-status=live  }}</ref> [[SQL queries]] and HTML output are usually done through wrapper functions that handle validation, escaping, filtering for prevention of [[cross-site scripting]] and [[SQL injection]].<ref>{{citation|url=https://blogs.techrepublic.com/security/?p=451|title=Five security tips from MediaWiki's lead developer|author=Perrin, Chad|date=April 30, 2008|publisher=Tech Republic}}{{Dead link|date=August 2022 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>  Many security issues have had to be patched after a MediaWiki version release,<ref>{{cite web |url=https://www.mediawiki.org/wiki/News |title=News |publisher=MediaWiki |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20141006102554/https://www.mediawiki.org/wiki/News |archive-date=October 6, 2014 |url-status=live  }}</ref> and accordingly MediaWiki.org states, "The most important security step you can take is to keep your software up to date" by subscribing to the announcement [[mailing list]] and installing security updates that are announced.<ref>{{cite web |url=https://www.mediawiki.org/wiki/Manual:Security |title=Manual:Security |publisher=MediaWiki |date=March 22, 2010 |access-date=May 30, 2010 |archive-url=https://web.archive.org/web/20141110162807/https://www.mediawiki.org/wiki/Manual:Security |archive-date=November 10, 2014 |url-status=live  }}</ref>

==Support==
Support for MediaWiki users consists of:
* MediaWiki.org, including the Support Desk.
* An official mailing list, Mediawiki-l.
* Several books have been written about MediaWiki administration,<ref>[https://www.mediawiki.org/wiki/Books_about_MediaWiki Books about MediaWiki] {{Webarchive|url=https://web.archive.org/web/20181227181503/https://www.mediawiki.org/wiki/Books_about_MediaWiki |date=December 27, 2018 }}, mediawiki.org</ref> including some free online books.<ref>{{cite book|url=https://en.wikibooks.org/wiki/MediaWiki_Administrator%27s_Handbook|title=MediaWiki Administrator's Handbook|publisher=[[Wikibooks]]|access-date=October 20, 2014|archive-url=https://web.archive.org/web/20141020055454/https://en.wikibooks.org/wiki/MediaWiki_Administrator%27s_Handbook|archive-date=October 20, 2014|url-status=live}}</ref><ref>{{citation|url=https://en.wikibooks.org/wiki/MediaWiki_User_Guide|publisher=Wikibooks|title=MediaWiki User Guide|access-date=October 20, 2014|archive-url=https://web.archive.org/web/20141020060147/https://en.wikibooks.org/wiki/MediaWiki_User_Guide|archive-date=October 20, 2014|url-status=live}}</ref>

==License==
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 www.mediawiki.org, is released under the [[Creative Commons license|Creative Commons BY-SA 4.0]] license, with a set of help pages intended to be freely copied into fresh wiki installations and/or distributed with MediaWiki software in the [[public domain]] instead to eliminate legal issues for wikis with other licenses.<ref>{{cite web |title=MediaWiki.org Project:Copyrights |url=https://www.mediawiki.org/w/index.php?title=Project:Copyrights&oldid=6078039 |url-status=live |archive-url=https://web.archive.org/web/20230823141546/https://www.mediawiki.org/w/index.php?title=Project:Copyrights&oldid=6078039 |archive-date=August 23, 2023 |access-date=August 23, 2023}}</ref><ref>{{cite web |url=https://www.mediawiki.org/w/index.php?title=Project:PD_help&oldid=320349 |title=Project:PD help |publisher=MediaWiki |access-date=May 30, 2010 |archive-date=October 29, 2020 |archive-url=https://web.archive.org/web/20201029184538/https://www.mediawiki.org/w/index.php?title=Project:PD_help&oldid=320349 |url-status=live }}</ref> MediaWiki's development has generally favored the use of [[Open file format|open-source media format]]s.<ref>{{citation|url=https://news.cnet.com/8301-17939_109-10103177-2.html|title=Wikipedia gears up for flood of video and photo files|date=November 19, 2008|author=Rafe Needleman|publisher=C-Net|access-date=April 23, 2010|archive-url=https://web.archive.org/web/20090806080149/https://news.cnet.com/8301-17939_109-10103177-2.html|archive-date=August 6, 2009|url-status=live}}</ref>

==Development==
MediaWiki has an active volunteer community for development and maintenance. MediaWiki developers are spread around the world, though with a majority in the United States and Europe. Face-to-face meetings and programming sessions for MediaWiki developers have been held once or several times a year since 2004.<ref>{{cite web |url=https://www.mediawiki.org/wiki/Events |title=Events |publisher=Mediawiki.org |access-date=December 27, 2018 |archive-date=December 27, 2018 |archive-url=https://web.archive.org/web/20181227181546/https://www.mediawiki.org/wiki/Events |url-status=live }}</ref>

Anyone can submit [[patch (computing)|patches]] to the project's [[Git]]/[[Gerrit (software)|Gerrit]] [[Repository (version control)|repository]].<ref>{{cite web |url=https://www.mediawiki.org/w/index.php?title=Development_policy&oldid=740327 |title=Development policy |publisher=MediaWiki |date=July 19, 2013 |access-date=August 4, 2013 |archive-date=May 10, 2017 |archive-url=https://web.archive.org/web/20170510130737/https://www.mediawiki.org/w/index.php?title=Development_policy&oldid=740327 |url-status=live }}</ref>
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.<ref>{{cite web |url=https://www.mediawiki.org/w/index.php?title=Summer_of_Code&oldid=663742 |title=Summer of Code |publisher=MediaWiki |date=March 26, 2013 |access-date=August 4, 2013 |archive-date=May 10, 2017 |archive-url=https://web.archive.org/web/20170510130220/https://www.mediawiki.org/w/index.php?title=Summer_of_Code&oldid=663742 |url-status=live }}</ref>
During the year prior to November 2012, there were about two hundred developers who had committed changes to the MediaWiki core or extensions.<ref>{{cite web |url=https://www.openhub.net/orgs/wikimedia |title=Wikimedia |publisher=Open Hub |access-date=November 15, 2012 |archive-url=https://web.archive.org/web/20170914173356/https://www.openhub.net/orgs/wikimedia |archive-date=September 14, 2017 |url-status=live  }} Approximate counts (not deduplicated) as of November 4, 2012: 139 for core, 155 for extensions supported by WMF, 190 and 42 for extensions only hosted on WMF's Git and SVN repositories respectively.</ref>
Major MediaWiki releases are generated approximately every six months by taking snapshots of the development branch, which is kept continuously in a runnable state;<ref name=":0">{{cite web |url=https://www.mediawiki.org/w/index.php?title=Version_lifecycle&oldid=2870502 |title=Version lifecycle |publisher=MediaWiki |date=September 5, 2018 |access-date=October 21, 2018 |archive-date=June 17, 2020 |archive-url=https://web.archive.org/web/20200617015450/https://www.mediawiki.org/w/index.php?title=Version_lifecycle&oldid=2870502 |url-status=live }}</ref> [[minor release]]s, or [[point release]]s, are issued as needed to correct [[Software bug|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.<ref name=":0" />
MediaWiki also has a public [[Bug tracking system|bug]] tracker, ''phabricator.wikimedia.org'', which runs [[Phabricator]]. The site is also used for [[Software feature|feature]] and [[Software enhancement|enhancement]] requests.

==History==
[[File:Magnus Manske.png|thumb|[[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 ([[Text file|.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 community|Wikipedia editor]]—began 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]] 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|Meta Wikipedia]] on November 9, 2001. There was a desire to have it implemented immediately on the English-language Wikipedia.<ref name="New script demand">{{cite web |last1=Bartlett |first1=Manning |title=Magnus's new script... |url=https://lists.wikimedia.org/pipermail/wikipedia-l/2001-November/000881.html |date=November 14, 2001 |website=Wikimedia Lists |publisher=Wikimedia Foundation |access-date=October 2, 2019 |archive-date=October 2, 2019 |archive-url=https://web.archive.org/web/20191002043502/https://lists.wikimedia.org/pipermail/wikipedia-l/2001-November/000881.html |url-status=live }}</ref> However, Manske was apprehensive about any potential [[Software bug|bugs]] harming the nascent website during the period of the final exams he had to complete immediately prior to Christmas;<ref name="Script response">{{cite web |last1=Manske |first1=Magnus |title=Magnus's new script... |url=https://lists.wikimedia.org/pipermail/wikipedia-l/2001-November/000882.html |date=November 14, 2001 |website=Wikimedia Lists |publisher=Wikimedia Foundation |access-date=October 2, 2019 |archive-date=October 2, 2019 |archive-url=https://web.archive.org/web/20191002043502/https://lists.wikimedia.org/pipermail/wikipedia-l/2001-November/000882.html |url-status=live }}</ref> 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".<ref>{{cite web |url = https://lists.wikimedia.org/pipermail/wikipedia-l/2003-July/011021.html |last = Mayer |first = Daniel |title = Phase IV, Wikibooks.org/.com and WikimediaFoundation.org/.com (was Wikis and uniformity) |work = Wikipedia-L mailing list |date=Jul 19, 2003 |access-date = January 18, 2015 |archive-date = July 12, 2017 |archive-url = https://web.archive.org/web/20170712002739/https://lists.wikimedia.org/pipermail/wikipedia-l/2003-July/011021.html |url-status = live }}</ref> The MediaWiki 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").<ref>{{cite web |url = https://www.mediawiki.org/wiki/Wikipmediawiki |title = Differences between Wikipedia, Wikimedia, MediaWiki, and wiki |publisher = MediaWiki |access-date = May 30, 2010 |archive-url = https://web.archive.org/web/20090701102809/https://www.mediawiki.org/wiki/Wikipmediawiki |archive-date = July 1, 2009 |url-status = live |df = mdy-all }}</ref> The first version of MediaWiki, 1.1, was released in December 2003.

[[File:MediaWiki logo.png|thumb|MediaWiki logo until April 1, 2021]]
The old [[Logo|product logo]] was created by [[Erik Möller]], using a flower photograph taken by [[Florence Devouard|Florence Nibart-Devouard]], and was originally submitted to the logo contest for a new [[metawiki:File talk:EloquenceSunflowerNew-Small.png|Wikipedia logo]], held from July 20 to August 27, 2003.<ref>{{Cite web|url=https://meta.wikimedia.org/wiki/International_logo_contest|title=International logo contest |website=Meta-Wiki |language=en|access-date=April 9, 2020|archive-date=May 9, 2020|archive-url=https://web.archive.org/web/20200509163823/https://meta.wikimedia.org/wiki/International_logo_contest|url-status=live}}</ref><ref>{{cite web |title = International logo contest/results |url = https://meta.wikimedia.org/w/index.php?title=International_logo_contest/Results&oldid=509000 |work = Meta-wiki |publisher = [[Wikimedia Foundation]] |date = January 10, 2007 |access-date = March 14, 2007 |archive-date = November 4, 2015 |archive-url = https://web.archive.org/web/20151104145339/https://meta.wikimedia.org/w/index.php?title=International_logo_contest%2FResults&oldid=509000 |url-status = live }}</ref> 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.<ref>{{cite web |title = Historical/Logo history |url = https://meta.wikimedia.org/w/index.php?title=Meta:Historical/Logo_history&oldid=513925 |publisher = [[Wikimedia Foundation]] |date = January 17, 2007 |access-date = March 14, 2007 |work = Meta-wiki |archive-date = November 4, 2015 |archive-url = https://web.archive.org/web/20151104145339/https://meta.wikimedia.org/w/index.php?title=Meta%3AHistorical%2FLogo_history&oldid=513925 |url-status = live }}</ref> The double square brackets ('''[[&nbsp;]]''') symbolize the [[Syntax of programming languages|syntax]] MediaWiki uses for creating [[hyperlink]]s to other wiki pages; while the [[sunflower]] represents the diversity of content on Wikipedia, its constant growth, and the wilderness.<ref>{{cite web |title = <nowiki>File talk:EloquenceSunflowerNew-Small.png</nowiki> – Meta |url = https://meta.wikimedia.org/w/index.php?title=File_talk:EloquenceSunflowerNew-Small.png&oldid=9331 |author = Erik Möller |work = Meta-wiki |publisher = [[Wikimedia Foundation]] |date = July 26, 2003 |access-date = February 3, 2013 |archive-date = January 30, 2016 |archive-url = https://web.archive.org/web/20160130205926/https://meta.wikimedia.org/w/index.php?title=File_talk:EloquenceSunflowerNew-Small.png&oldid=9331 |url-status = live }}</ref>

Later, {{Visible anchor|Brooke Vibber|Brion Vibber}}, the [[Chief technology officer|chief technical officer]] of the [[Wikimedia Foundation]],<ref>{{cite book |title = Everything Is Miscellaneous: The Power of the New Digital Disorder |author = David Weinberger | author-link = David Weinberger |year = 2007 |publisher = Times Books |isbn = 978-0-8050-8043-8 |page = [https://archive.org/details/everythingismisc00davi/page/99 99] |title-link = Everything Is Miscellaneous: The Power of the New Digital Disorder }}</ref> took up the role of [[release manager]].<ref name="MediaWiki_history">{{cite web |url = //www.mediawiki.org/w/index.php?title=MediaWiki_history&oldid=618636 |access-date = August 4, 2013 |title = MediaWiki history |work = MediaWiki website |archive-date = October 27, 2020 |archive-url = https://web.archive.org/web/20201027154036/https://www.mediawiki.org/w/index.php?title=MediaWiki_history&oldid=618636 |url-status = live }}</ref><ref name="WikipediaandMediaWikiTalk">{{cite web |url = https://www.youtube.com/watch?v=DWef69ItVrU |date = April 28, 2006 |access-date = September 23, 2009 |title = Wikipedia and MediaWiki |work = Presentation MediaWiki development (video) |archive-url = https://web.archive.org/web/20110414151917/https://www.youtube.com/watch?v=DWef69ItVrU |archive-date = April 14, 2011 |url-status = live |df = mdy-all }}</ref>

Major milestones in MediaWiki's development have included: the [[Categorization|categorization system]] (2004); [[Parsing|parser]] functions, (2006); [[Flagged Revisions]], (2008);<ref name="Introducing">{{citation |title = Introducing new features to Wikipedia |author1 = M Schindler |author2 = D Vrandecic |publisher = Proceedings of WebSci |year = 2009 |url = https://www.researchgate.net/publication/224219255 |access-date = June 24, 2018 |archive-url = https://web.archive.org/web/20180624093211/https://www.researchgate.net/publication/224219255_Introducing_New_Features_to_Wikipedia_Case_Studies_for_Web_Science |archive-date = June 24, 2018 |url-status = live |df = mdy-all }}</ref> the "''ResourceLoader''", a delivery system for [[CSS]] and JavaScript (2011);<ref>{{cite web |url=https://www.mediawiki.org/wiki/ResourceLoader |title=MediaWiki ResourceLoader |publisher=Mediawiki.org |access-date=July 6, 2013 |archive-url=https://web.archive.org/web/20130308030735/https://www.mediawiki.org/wiki/ResourceLoader |archive-date=March 8, 2013 |url-status=live  }}</ref> and the [[VisualEditor]], a "what you see is what you get" ([[WYSIWYG]]) editing platform (2013).<ref>{{Cite web|url = https://www.mediawiki.org/wiki/VisualEditor|publisher = MediaWiki|access-date = September 15, 2013|title = VisualEditor – MediaWiki|archive-url = https://web.archive.org/web/20130927190403/https://www.mediawiki.org/wiki/VisualEditor|archive-date = September 27, 2013|url-status = live|df = mdy-all}}</ref>

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.<ref name="new_logo">{{cite web |last1=Sarabadani |first1=Amir |title=Logo of MediaWiki has changed |url=https://lists.wikimedia.org/pipermail/mediawiki-l/2021-March/048685.html |publisher=Wikimedia Foundation |access-date=April 2, 2021 |date=March 31, 2021 |archive-date=April 2, 2021 |archive-url=https://web.archive.org/web/20210402053427/https://lists.wikimedia.org/pipermail/mediawiki-l/2021-March/048685.html |url-status=live }}</ref>

==Sites using MediaWiki==
{{See also|Category:MediaWiki websites}}
[[File:Wikia Block user.jpeg|thumb|[[Fandom (website)|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 (website)|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]].<ref>[https://www.mediawiki.org/wiki/MediaWiki_testimonials MediaWiki testimonials] {{Webarchive|url=https://web.archive.org/web/20120111223511/https://www.mediawiki.org/wiki/MediaWiki_testimonials |date=January 11, 2012 }}, mediawiki.org</ref><ref>{{cite web|url=https://socialmedia.biz/2010/07/08/the-story-of-intelpedia-a-model-corporate-wiki/|title=The story of Intelpedia: A model corporate wiki|work=Socialmedia.biz|access-date=August 16, 2013|archive-url=https://web.archive.org/web/20130916232246/https://socialmedia.biz/2010/07/08/the-story-of-intelpedia-a-model-corporate-wiki/|archive-date=September 16, 2013|url-status=live}}</ref>

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 System|United Nations agencies]] such as the [[United Nations Development Programme]] and [[United Nations International Research and Training Institute for the Advancement of Women|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."<ref>{{cite web |url=https://journal.km4dev.org/journal/index.php/km4dj/article/view/99/159 |title=A stealth transformation: introducing wikis to the UN |author1=A. Maron |author2=M. Maron |publisher=Knowledge Management for Development Journal |year=2007 |access-date=October 9, 2010 |archive-url=https://web.archive.org/web/20110504030508/https://journal.km4dev.org/journal/index.php/km4dj/article/view/99/159 |archive-date=May 4, 2011 |url-status=dead }}</ref>

The [[Free Software Foundation]] uses MediaWiki to implement the [[LibrePlanet]] site.<ref>{{cite web|url=https://www.libreplanet.org|title=LibrePlanet Homepage|access-date=December 10, 2018|archive-url=https://web.archive.org/web/20110318110137/https://libreplanet.org/|archive-date=March 18, 2011|url-status=live}}</ref>

==Comparison to other online collaboration software==
{{Main|Comparison of wiki software}}

Users of online [[collaboration software]] are familiar with MediaWiki's functions and layout due to its noted use on Wikipedia. A 2006 overview of social software in academia observed that "Compared to other wikis, MediaWiki is also fairly aesthetically pleasing, though simple, and has an easily customized side menu and [[style sheet (web development)|stylesheet]]."<ref>{{citation|title=Social Software in Academia|author=Bryant, Todd|publisher=Educause Quarterly|year=2006|url=https://net.educause.edu/ir/library/pdf/EQM0627.pdf|access-date=April 23, 2010|archive-url=https://web.archive.org/web/20091222054230/https://net.educause.edu/ir/library/pdf/eqm0627.pdf|archive-date=December 22, 2009|url-status=dead}}</ref> However, in one assessment in 2006, [[Confluence (software)|Confluence]] was deemed to be a superior product due to its very usable API and ability to better support multiple wikis.<ref name=Wikido/>

A 2009 study at the [[University of Hong Kong]] compared [[TWiki]] to MediaWiki. The authors noted that TWiki has been considered as a collaborative tool for the development of educational papers and technical projects, whereas MediaWiki's most noted use is on Wikipedia. Although both platforms allow discussion and tracking of progress, TWiki has a "Report" part that MediaWiki lacks. Students perceived MediaWiki as being easier to use and more enjoyable than TWiki. When asked whether they recommended using MediaWiki for [[knowledge management]] course group project, 15 out of 16 respondents expressed their preference for MediaWiki giving answers of great certainty, such as "of course", "for sure".<ref>{{citation|url=https://www.edu.hku.hk/samchu/docs/2009_user_experiences.pdf |author1=Liang, M. |author2=Chu, S. |author3=Siu, F. |author4=Zhou, A. |date=Dec 3–4, 2009 |title=Comparing User Experiences in Using Twiki & Mediawiki to Facilitate Collaborative Learning |publisher=Proceedings of the 2009 International Conference on Knowledge Management |url-status=dead |archive-url=https://web.archive.org/web/20110514030607/https://www.edu.hku.hk/samchu/docs/2009_user_experiences.pdf |archive-date=May 14, 2011 }}</ref> TWiki and MediaWiki both have flexible plug-in architecture.<ref>{{citation|title=Company-Wiki as a knowledge transfer instrument for reducing the shortage of skilled workers|publisher=Institute of Technology and Education|author=Schulz, Judith|year=2009|url=https://elib.suub.uni-bremen.de/ip/docs/00010611.pdf|access-date=April 25, 2010|archive-url=https://web.archive.org/web/20160304092952/https://elib.suub.uni-bremen.de/ip/docs/00010611.pdf|archive-date=March 4, 2016|url-status=live}}</ref>

A 2009 study that compared students' experience with MediaWiki to that with [[Google Documents|Google Docs]] found that students gave the latter a much higher rating on user-friendly layout.<ref>{{citation|author1=Chu, S. |author2=Kennedy, D. |author3=Mak, M.|title=MediaWiki and Google Docs as online collaboration tools for group project co-construction|publisher=Proceedings of the 2009 International Conference on Knowledge Management|date=December 3–4, 2009|url=https://www.edu.hku.hk/samchu/docs/2009_mediawiki.pdf|access-date=April 23, 2010|archive-url=https://web.archive.org/web/20110514030658/https://www.edu.hku.hk/samchu/docs/2009_mediawiki.pdf|archive-date=May 14, 2011|url-status=dead}}</ref>

A 2021 study conducted by the [[National Nuclear Energy Commission|Brazilian Nuclear Engineering Institute]] compared a MediaWiki-based [[Knowledge management|knowledge management system]] against two others that were based on [[DSpace]] and [[Open Journal Systems]], respectively.<ref name=":1">{{Cite journal|last1=Grecco|first1=Claudio Henrique dos Santos|last2=Augusto|first2=Silas Cordeiro|last3=Souza|first3=Jaqueline Tavares Viana de|last4=Carvalho|first4=Paulo Victor Rodrigues|last5=Davila|first5=Adriana Loureiro|date=July 25, 2021|title=A Method for the evaluation of knowledge management systems|url=https://www.bjrs.org.br/revista/index.php/REVISTA/article/view/1250|journal=Brazilian Journal of Radiation Sciences|language=en|volume=9|issue=2B|doi=10.15392/bjrs.v9i2B.1250|s2cid=237733021|issn=2319-0612|access-date=November 12, 2021|archive-date=November 12, 2021|archive-url=https://web.archive.org/web/20211112114628/https://www.bjrs.org.br/revista/index.php/REVISTA/article/view/1250|url-status=live|doi-access=free}}</ref> It highlighted ease of use as an advantage of the MediaWiki-based system, noting that because the Wikimedia Foundation had been developing MediaWiki for a site aimed at the general public (Wikipedia), "its user interface was designed to be more user-friendly from start, and has received large user feedback over a long time", in contrast to DSpace's and OJS's focus on niche audiences.<ref name=":1" />

==See also==
{{Portal|Free and open-source software}}
* [[List of content management systems]]
* [[List of wiki software]]
* [[BlueSpice]]
* [[Semantic MediaWiki]]
* [[XOWA]] – for viewing Wikipedia and other wikis offline
* [[PHP]] – a programming language that powers MediaWiki

==References==
{{Reflist}}

==External links==
{{Sister project links|d=Q83|c=Category:MediaWiki|mw=Manual:What is MediaWiki?|m=MediaWiki|voy=no|species=no|s=no|n=no}}
* {{Official website|2=MediaWiki homepage}}
{{Wikipedia}}
{{Wiki software}}
{{Wikimedia Foundation}}

{{Authority control}}

[[Category:MediaWiki| ]]
[[Category:2002 software]]
[[Category:Articles containing video clips]]
[[Category:Articles with example code]]
[[Category:Collaborative software]]
[[Category:Cross-platform free software]]
[[Category:Free content management systems]]
[[Category:Free software programmed in PHP]]
[[Category:Free wiki software]]
[[Category:Multilingual websites]]
[[Category:Version control systems]]
[[Category:History of Wikipedia]]
[[Category:Software using the GNU General Public License]]