Wiki software (also known as a wiki engine or a wiki application), is

collaborative software Collaborative software or groupware is application software designed to help people working on a common task to attain their goals. One of the earliest definitions of groupware is "intentional group processes plus software to support them". As re ...

that runs a

wiki A wiki ( ) is an online hypertext publication collaboratively edited and managed by its own audience, using a web browser. A typical wiki contains multiple pages for the subjects or scope of the project, and could be either open to the pu ...

, which allows the users to create and collaboratively edit pages or entries via a

web browser A web browser is application software for accessing websites. When a user requests a web page from a particular website, the browser retrieves its files from a web server and then displays the page on the user's screen. Browsers are used on ...

. A wiki system is usually a

web application A web application (or web app) is application software that is accessed using a web browser. Web applications are delivered on the World Wide Web to users with an active network connection. History In earlier computing models like client-serve ...

that runs on one or more

web server A web server is computer software and underlying hardware that accepts requests via HTTP (the network protocol created to distribute web content) or its secure variant HTTPS. A user agent, commonly a web browser or web crawler, initi ...

s. The content, including previous revisions, is usually stored in either a

file system In computing, file system or filesystem (often abbreviated to fs) is a method and data structure that the operating system uses to control how data is stored and retrieved. Without a file system, data placed in a storage medium would be one lar ...

or a

database In computing, a database is an organized collection of data stored and accessed electronically. Small databases can be stored on a file system, while large databases are hosted on computer clusters or cloud storage. The design of databases spa ...

. Wikis are a type of

web content management system A web content management system (WCM or WCMS) is a software content management system (CMS) specifically for web content. It provides website authoring, collaboration, and administration tools that help users with little knowledge of web programm ...

, and the most commonly supported off-the-shelf software that

web hosting A web hosting service is a type of Internet hosting service that hosts websites for clients, i.e. it offers the facilities required for them to create and maintain a site and makes it accessible on the World Wide Web. Companies providing we ...

facilities offer. There are dozens of actively maintained wiki engines. They vary in the platforms they run on, the

programming language A programming language is a system of notation for writing computer programs. Most programming languages are text-based formal languages, but they may also be graphical. They are a kind of computer language. The description of a programming l ...

they were developed in, whether they are

open-source Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use the source code, design documents, or content of the product. The open-source model is a decentralized sof ...

or proprietary, their support for natural language characters and conventions, and their assumptions about technical versus social control of editing.

History

The first generally recognized "wiki" application,

WikiWikiWeb The WikiWikiWeb is the first wiki, or user-editable website. It was launched on 25 March 1995 by programmer Ward Cunningham to accompany the Portland Pattern Repository website discussing software design patterns. The name ''WikiWikiWeb'' orig ...

, was created by American computer programmer Ward Cunningham in 1994 and launched on c2.com in 1995. "WikiWikiWeb" was also the name of the wiki that ran on the software, and in the first years of wikis' existence there was no great distinction made between the contents of wikis and the software they ran on, possibly because almost every wiki ran on its own customized software. Wiki software originated from older

version control In software engineering, version control (also known as revision control, source control, or source code management) is a class of systems responsible for managing changes to computer programs, documents, large web sites, or other collections o ...

systems used for documentation and software in the 1980s. By the mid-1990s these generally had

interfaces. However, they lacked the ability to easily create links between internal pages without writing

HTML The HyperText Markup Language or HTML is the standard markup language for documents designed to be displayed in a web browser. It can be assisted by technologies such as Cascading Style Sheets (CSS) and scripting languages such as JavaScri ...

code. For WikiWikiWeb, the

CamelCase Camel case (sometimes stylized as camelCase or CamelCase, also known as camel caps or more formally as medial capitals) is the practice of writing phrases without spaces or punctuation. The format indicates the separation of words with a single c ...

naming convention was used to indicate internal links, without requiring HTML code. By the time

MediaWiki MediaWiki is a Free and open-source software, free and open-source wiki software. It is used on Wikipedia and almost all other Wikimedia movement, Wikimedia Website, websites, including Wiktionary, Wikimedia Commons and Wikidata; these sit ...

appeared, this convention had been largely abandoned in favor of explicitly marking links in edited

source code In computing, source code, or simply code, is any collection of code, with or without comment (computer programming), comments, written using a human-readable programming language, usually as plain text. The source code of a Computer program, p ...

with double square brackets. Page names thus did not interrupt the flow of English and could follow standard English capitalization convention. Case-insensitivity on the first letter but not subsequent letters supported standard English capitalization conventions and let writers author their pages in ordinary English, with the linking of particular words and phrases afterward. This proved to be the critical change that allowed ordinary authors of English to write wiki pages, and non-technical users to read them. This policy was extended to other natural languages, avoiding the use of unusual-looking text or awkward capitalization that violates the language's own rules. Over the next 10 years, many more wiki applications were written, in a variety of

s. After 2005, there began to be a move toward increasing consolidation and standardization: many less-popular wiki applications were gradually abandoned, and fewer new applications were created. Relatively few of the wiki engines currently in use were created after 2006. Some

content management system A content management system (CMS) is computer software used to manage the creation and modification of digital content ( content management).''Managing Enterprise Content: A Unified Content Strategy''. Ann Rockley, Pamela Kostur, Steve Manning. New ...

s, such as

Microsoft SharePoint SharePoint is a web-based collaborative platform that integrates natively with Microsoft Office. Launched in 2001, SharePoint is primarily sold as a document management and storage system, but the product is highly configurable and its usage v ...

, have also adopted wiki-like functionality.

Data compatibility

In general new wiki engines have not followed the data formats (

wiki markup A wiki ( ) is an online hypertext publication collaboratively edited and managed by its own audience, using a web browser. A typical wiki contains multiple pages for the subjects or scope of the project, and could be either open to the p ...

languages) of the existing engines, making them of limited use for those who have already invested in large

knowledge base A knowledge base (KB) is a technology used to store complex structured and unstructured information used by a computer system. The initial use of the term was in connection with expert systems, which were the first knowledge-based systems. ...

s in existing software. As a rule newer wiki projects have not succeeded in attracting large numbers of users from the existing wiki software base. The most well-known data format arguably is MediaWiki's, and correspondingly has been reimplemented in other wikis: *

WordPress WordPress (WP or WordPress.org) is a free and open-source software, free and open-source content management system (CMS) written in PHP, hypertext preprocessor language and paired with a MySQL or MariaDB database with supported secure hypert ...

has extensions to display and edit MediaWiki-format pages, and to frame MediaWiki. * Jamwiki is a MediaWiki clone in

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mo ...

, that supports MediaWiki-format pages but not extensions. * Other commercial projects or clones often (or have in the past) follow the MediaWiki format.

BlueSpice MediaWiki BlueSpice MediaWiki (BlueSpice for short) is free wiki software based on the MediaWiki engine and licensed with the GNU General Public License. It is especially developed for businesses as an enterprise wiki distribution for MediaWiki and used in ...

is the only such software with a free version available. None of these alternatives support the extensions available under standard MediaWiki, some of which extend or alter its data format. In 2007 a project named (Wiki) Creole to create a standardized markup language for wikis was completed. As of 2022, the effort has had significant technical success, gaining support through implementation in many engines, but limited social success as it is still relatively unused and unknown, having few cross-markup conversion tools for migrating existing

s to it and no major engines using it as their native markup syntax.

Types of usage

There are essentially three types of usage for wiki software: public-facing wikis with a potentially large community of readers and editors, private

enterprise wiki Enterprise (or the archaic spelling Enterprize) may refer to: Business and economics Brands and enterprises * Enterprise GP Holdings, an energy holding company * Enterprise plc, a UK civil engineering and maintenance company * Enterprise ...

s for

data management Data management comprises all disciplines related to handling data as a valuable resource. Concept The concept of data management arose in the 1980s as technology moved from sequential processing (first punched cards, then magnetic tape) to ...

by corporations and other organizations, and

personal wiki A personal wiki is wiki software that allows individual users to organize information on their desktop or mobile computing devices in a manner similar to community wikis, but without collaborative software or multiple users. Personal wiki soft ...

s, meant to be used by a single person to manage notes, and usually run on a

desktop A desktop traditionally refers to: * The surface of a desk (often to distinguish office appliances that fit on a desk, such as photocopiers and printers, from larger equipment covering its own area on the floor) Desktop may refer to various compu ...

. Some wiki software is specifically geared for one of the usage types, while other software can be used for all three, but contains functionality, either in its core or through plugins, that help with one or more of the usage types.

Public wikis

Public wikis are usually open to the public to read, edit and comment on some or all of the article space of each wiki. Many offer registration to offer further access and controls to each user and a few have, in-part commercialised aspects or further access, such as the popular wiki farm,

Fandom A fandom is a subculture composed of fans characterized by a feeling of empathy and camaraderie with others who share a common interest. Fans typically are interested in even minor details of the objects of their fandom and spend a significan ...

is by far the most dominant software as it powers

Wikipedia Wikipedia is a multilingual free online encyclopedia written and maintained by a community of volunteers, known as Wikipedians, through open collaboration and using a wiki-based editing system. Wikipedia is the largest and most-read ref ...

, consistently and by a large margin, the most visited public wiki, it also powers many other public wikis as well.Breakdown of active wikis on WikiIndex
/ref> Other wiki engines used regularly for public wikis include

MoinMoin MoinMoin is a wiki engine implemented in Python, initially based on the PikiPiki wiki engine. Its name is a play on the North German greeting ''Moin'', repeated as in WikiWiki. The MoinMoin code is licensed under the GNU General Public License ...

and PmWiki, along with many others. Other Internet websites, based on wiki software, include

encyclopedias An encyclopedia (American English) or encyclopædia (British English) is a reference work or compendium providing summaries of knowledge either general or special to a particular field or discipline. Encyclopedias are divided into articles ...

such as Sensei's Library, Parlia, and WikiTree.

Enterprise wikis

Enterprise Enterprise (or the archaic spelling Enterprize) may refer to: Business and economics Brands and enterprises * Enterprise GP Holdings, an energy holding company * Enterprise plc, a UK civil engineering and maintenance company * Enterprise ...

wiki software is software intended to be used in a corporate (or organizational) context, especially to enhance internal

knowledge sharing Knowledge sharing is an activity through which knowledge (namely, information, skills, or expertise) is exchanged among people, friends, peers, families, communities (for example, Wikipedia), or within or between organizations. It bridges the ind ...

. It tends to have a greater emphasis on features like access control, integration with other software, and

document management A document management system (DMS) is usually a computerized system used to store, share, track and manage files or documents. Some systems include history tracking where a log of the various versions created and modified by different users is r ...

. Most proprietary wiki applications specifically market themselves as enterprise solutions, including

Socialtext Socialtext Incorporated was a company based in Palo Alto, California, that produced enterprise social software for companies. It offered an integrated suite of wiki tools and social software applications, including microblogging, user profiles, ...

, Jive, Traction TeamPage,

Notion Notion or Notions may refer to: Software * Notion (music software), a music composition and performance program * Notion (productivity software), a note-taking and project-management program from Notion Labs Inc. * Notion (window manager), the ...

, and Nuclino. Increasingly offerings appear which use the name 'wiki' but do not offer basic elements common to established wikis, like Wiki Markup and Link-first workflow as in

Confluence In geography, a confluence (also: ''conflux'') occurs where two or more flowing bodies of water join to form a single channel. A confluence can occur in several configurations: at the point where a tributary joins a larger river ( main stem); ...

(since 2018), or Version Control of

Full Text Search In text retrieval, full-text search refers to techniques for searching a single computer-stored document or a collection in a full-text database. Full-text search is distinguished from searches based on metadata or on parts of the original tex ...

Microsoft Teams Microsoft Teams is a proprietary business communication platform developed by Microsoft, as part of the Microsoft 365 family of products. Teams primarily competes with the similar service Slack, offering workspace chat and videoconferenci ...

. In addition, some open source wiki applications also describe themselves as enterprise solutions, including XWiki,

Foswiki Foswiki is an enterprise wiki, typically used to run a collaboration platform, knowledge base or document management system. Users can create wiki applications using the Topic Markup Language (TML), and developers can extend its functionality ...

TWiki TWiki is a Perl-based structured wiki application, typically used to run a collaboration platform, knowledge or document management system, a knowledge base, or team portal. Users can create wiki pages using the TWiki Markup Language, and ...

, and BlueSpice. Some open-source wiki applications, though they do not specifically bill themselves as enterprise solutions, have marketing materials geared for enterprise users, like

Tiki Wiki CMS Groupware Tiki Wiki CMS Groupware or simply Tiki, originally known as TikiWiki, is a free and open source Wiki-based content management system and online office suite written primarily in PHP and distributed under the GNU Lesser General Public License (LGP ...

and

. Many other wiki applications have also been used within enterprises. Among the many companies and government organizations that use wikis internally are Adobe Systems,

Amazon.com Amazon.com, Inc. ( ) is an American multinational technology company focusing on e-commerce, cloud computing, online advertising, digital streaming, and artificial intelligence. It has been referred to as "one of the most influential econom ...

Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the devel ...

Microsoft Microsoft Corporation is an American multinational corporation, multinational technology company, technology corporation producing Software, computer software, consumer electronics, personal computers, and related services headquartered at th ...

, and the

United States intelligence community United may refer to: Places * United, Pennsylvania, an unincorporated community * United, West Virginia, an unincorporated community Arts and entertainment Films * United (2003 film), ''United'' (2003 film), a Norwegian film * United (2011 film) ...

. Within organizations, wikis may either add to or replace centrally managed content management systems. Their decentralized nature allows them, in principle, to disseminate needed information across an organization more rapidly and more cheaply than a centrally controlled knowledge repository. Wikis can also be used for

project management Project management is the process of leading the work of a team to achieve all project goals within the given constraints. This information is usually described in project documentation, created at the beginning of the development process. T ...

customer relationship management Customer relationship management (CRM) is a process in which a business or other organization administers its interactions with customers, typically using data analysis to study large amounts of information. CRM systems compile data from a r ...

enterprise resource planning Enterprise resource planning (ERP) is the integrated management of main business processes, often in real time and mediated by software and technology. ERP is usually referred to as a category of business management software—typically a sui ...

, and many other kinds of data management. Features of wikis which can serve an enterprise include: * Entering information into quick and easy-to-create pages, including hyperlinks to other corporate information systems like people directories, CMS, applications, and thus to facilitate the buildup of useful knowledge bases. * Reduces

e-mail Electronic mail (email or e-mail) is a method of exchanging messages ("mail") between people using electronic devices. Email was thus conceived as the electronic ( digital) version of, or counterpart to, mail, at a time when "mail" mean ...

overload. Wikis allow all relevant information to be shared by people working on a given project. Conversely, only the wiki users interested in a given project need look at its associated wiki pages, in contrast to high-traffic mailing lists which may burden subscribers with many messages, regardless of their relevance. It is also very useful for the project manager to have all the communication stored in one place, which allows them to link the responsibility for every action taken to a particular team member. * Organizes information. Wikis help users structure information into discoverable and searchable categories. These may arise from users in a bottom-up way. Users can create lists, tables, timelines and other ways of expressing order. * Builds consensus. Wikis allow structuring the expression of views, on a topic being considered by authors, on the same page. This feature is very useful when writing documentation, preparing presentations, when author opinions differ, and so on. * Access levels by rights and roles. Users can be denied access to view and/or edit given pages, depending upon their department or role within the organization. * Knowledge management with comprehensive searches. This includes document management, project management, and knowledge repositories useful during times of employee turnover or retirement.

Personal wikis

Software that is specifically designed for running personal wikis includes

Tomboy A tomboy is a term for a girl or a young woman with masculine qualities. It can include wearing androgynous or unfeminine clothing and actively engage in physical sports or other activities and behaviors usually associated with boys or men ...

, PmWiki, and

ConnectedText ConnectedText (also abbreviated as CT) is a personal wiki which runs on Windows. Articles are written in plain text in CT's own markup language. When viewing articles they are styled by a standard HTML CSS file. The markup language contains ma ...

(now discontinued). Other, more general, wiki applications have components geared for individual users, including

(which offers a "DesktopEdition"), and

TiddlyWiki TiddlyWiki is a personal wiki and a non-linear notebook for organising and sharing complex information. It is an open-source single page application wiki in the form of a single HTML file that includes CSS, JavaScript, embedded files such as im ...

Editing

Most wiki software uses a special syntax, known as

, for users to format the text, instead of requiring them to enter in

. Some wiki applications also include a

WYSIWYG In computing, WYSIWYG ( ), an acronym for What You See Is What You Get, is a system in which editing software allows content to be edited in a form that resembles its appearance when printed or displayed as a finished product, such as a printed d ...

editor, either instead of or in addition to the wiki markup editing. Based on the atomic property of database systems, any edit should be traced. On wiki software, the

chronology Chronology (from Latin ''chronologia'', from Ancient Greek , ''chrónos'', "time"; and , '' -logia'') is the science of arranging events in their order of occurrence in time. Consider, for example, the use of a timeline or sequence of events. ...

of edits (e.g. published by Internet users) in any given article may be locally saved with a common

.xml Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing arbitrary data. It defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. ...

file extension by people having administrator rights.

Hosted application

There are a variety of

wiki hosting service A wiki hosting service, or wiki farm, is a server or an array of servers that offers users tools to simplify the creation and development of individual, independent wikis. Wiki farms are not to be confused with wiki "families", a more generic t ...

s, otherwise known as wiki farms, that host users' wikis on a server. Some wiki software is only available in hosted form:

PBworks PBworks (formerly PBwiki) is a commercial real-time collaborative editing (RTCE) system created by David Weekly, with Ramit Sethi and Nathan Schmidt, who joined shortly thereafter as co-founders. Based in San Mateo, California, United States, t ...

Wetpaint Wetpaint was an Internet company and a wholly owned subsidiary of Function(X). Founded in 2005, Wetpaint both published the website Wetpaint Entertainment, focused on entertainment news, and developed a proprietary technology platform, the Socia ...

and Wikispaces are all examples of wiki hosting services that run on code that is only available on those sites. Other wiki software is available in both hosted and downloadable form, including

and XWiki.

Additional features

Content-management features

Wiki software can include features that come with traditional content management systems, such as calendars, to-do lists,

blog A blog (a truncation of "weblog") is a discussion or informational website published on the World Wide Web consisting of discrete, often informal diary-style text entries (posts). Posts are typically displayed in reverse chronological order ...

s and discussion forums. All of these can either be stored via versioned wiki pages, or simply be a separate piece of functionality. Software that supports blogs with wiki-style editing and versioning is sometimes known as "bliki" software. Tiki Wiki CMS Groupware is an example of wiki software that is designed to support such features at its core. Many of the enterprise wiki applications, such as

and

SharePoint SharePoint is a web-based collaborative platform that integrates natively with Microsoft Office. Launched in 2001, SharePoint is primarily sold as a document management and storage system, but the product is highly configurable and its usage v ...

, also support such features, as do open-source applications like

and XWiki, via

plugins Plug-in, plug in or plugin may refer to: * Plug-in (computing) is a software component that adds a specific feature to an existing computer program. ** Audio plug-in, adds audio signal processing features ** Photoshop plugin, a piece of software t ...

Scripting

Some wiki applications let users embed scripting-style calls into wiki pages, which are processed by the wiki's parser and run either when the page is saved or when it is displayed. XWiki and

are examples of such applications. Specifically XWiki offers support for the following scripting languages:

Groovy ''Groovy'' (or, less commonly, ''groovie'' or ''groovey'') is a slang colloquialism popular during the 1950s, '60s and '70s. It is roughly synonymous with words such as "excellent", "fashionable", or "amazing", depending on context. History The ...

Velocity Velocity is the directional speed of an object in motion as an indication of its rate of change in position as observed from a particular frame of reference and as measured by a particular standard of time (e.g. northbound). Velocity i ...

Ruby A ruby is a pinkish red to blood-red colored gemstone, a variety of the mineral corundum (aluminium oxide). Ruby is one of the most popular traditional jewelry gems and is very durable. Other varieties of gem-quality corundum are called sapp ...

, Python,

PHP PHP is a General-purpose programming language, general-purpose scripting language geared toward web development. It was originally created by Danish-Canadian programmer Rasmus Lerdorf in 1993 and released in 1995. The PHP reference implementati ...

or more generally any

JSR223 Scripting for the Java Platform is a framework for embedding scripts into Java source code. There is no requirement for a given Java virtual machine (JVM) to include any engines by default, but the Oracle JVM (Java 6 and later) includes a JavaScr ...

scripting language.

Semantic annotation

Wiki software can let users store data via the wiki, in a way that can be exported via the Semantic Web, or queried internally within the wiki. A wiki that allows such annotation is known as a

semantic wiki A semantic wiki is a wiki that has an underlying model of the knowledge described in its pages. Regular, or syntactic, wikis have structured text and untyped hyperlinks. Semantic wikis, on the other hand, provide the ability to capture or identif ...

. The current best-known semantic wiki software is

Semantic MediaWiki Semantic MediaWiki (SMW) is an extension to MediaWiki that allows for annotating semantic data within wiki pages, thus turning a wiki that incorporates the extension into a semantic wiki. Data that has been encoded can be used in semantic sear ...

, a plugin to MediaWiki.

Mobile access

Some wiki software have special handling for accessing by mobile devices, such as

mobile phone A mobile phone, cellular phone, cell phone, cellphone, handphone, hand phone or pocket phone, sometimes shortened to simply mobile, cell, or just phone, is a portable telephone that can make and receive telephone call, calls over a radio freq ...

s. This is usually done by displaying conservative

coding.

Offline viewing and editing

Various approaches to providing wiki functionality when the user is not online have been tried. For users who need to simply read the wiki's content when offline, a copy of the content can often be made easily; in the case of Wikipedia, CD-ROMs and printed versions have been made of parts of Wikipedia's content. Allowing offline editing, however (where the changes are synchronized when the user is back online), is a much more difficult process. One approach to doing this is using a

distributed revision control system In software development, distributed version control (also known as distributed revision control) is a form of version control in which the complete codebase, including its full history, is mirrored on every developer's computer. Compared to centr ...

as a backend of the wiki, in

peer-to-peer Peer-to-peer (P2P) computing or networking is a distributed application architecture that partitions tasks or workloads between peers. Peers are equally privileged, equipotent participants in the network. They are said to form a peer-to-peer ...

style. With this approach, there is no central store of the wiki's content; instead, every user keeps a complete copy of the wiki locally, and the software handles merging and propagating of changes when they are made. This is the approach taken by the

ikiwiki ikiwiki is a free and open-source wiki application, designed by Joey Hess. It is licensed under the terms of the GNU General Public License, version 2 or later. ikiwiki is written in Perl, although external plugins can be implemented in any langu ...

engine (which can use the distributed revision control system

Git Git () is a distributed version control system: tracking changes in any set of files, usually used for coordinating work among programmers collaboratively developing source code during software development. Its goals include speed, data integ ...

as its back-end), and Code Co-op (a distributed revision control system that includes a wiki component).

Distributing and decentralizing

Wiki software can be

distributed Distribution may refer to: Mathematics *Distribution (mathematics), generalized functions used to formulate solutions of partial differential equations *Probability distribution, the probability of a particular value or value range of a varia ...

. XWiki is able to function in this way. Smallest Federated Wiki promotes a federation of wiki servers, There has also been research done on allowing Wikipedia to be run as a decentralized wiki.Wikipedia Workload Analysis for Decentralized Hosting
Guido Urdaneta, Guillaume Pierre, Maarten van Steen, ''Elsevier Computer Networks'' 53(11), pp. 1830–1845, July 2009

Notes

References

* Andersen, Espen (2005)
Using Wikis in a Corporate Context
In ''Handbuch E-Learning''. A. Hohenstein and K. Wilbers (eds). Cologne, WoltersKluwer. 5.8: 15. * Guy, Marieke (2006)
Wiki or Won't He? A Tale of Public Sector Wikis
Ariadne Issue 49. * Grzeganek, K.; Frost, I.; Gross, D (2011)
Spoilt for Choice - Wiki Software for Knowledge Management in Organisations
Community of Knowledge. {{WebManTools Web portals Information technology management Wikis by genre