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." Regar ...

that runs a

wiki A wiki ( ) is a form of hypertext publication on the internet which is collaboratively edited and managed by its audience directly through a web browser. A typical wiki contains multiple pages that can either be edited by the public or l ...

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

web browser A web browser, often shortened to browser, is an application 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 scr ...

. A wiki system is usually a

web application A web application (or web app) is application software that is created with web technologies and runs via a web browser. Web applications emerged during the late 1990s and allowed for the server to dynamically build a response to the request, ...

that runs on one or more

web server A web server is computer software and underlying Computer hardware, hardware that accepts requests via Hypertext Transfer Protocol, HTTP (the network protocol created to distribute web content) or its secure variant HTTPS. A user agent, co ...

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

database In computing, a database is an organized collection of data or a type of data store based on the use of a database management system (DBMS), the software that interacts with end users, applications, and the database itself to capture and a ...

. 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 program ...

, 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 web ho ...

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. Programming languages are described in terms of their Syntax (programming languages), syntax (form) and semantics (computer science), semantics (meaning), usually def ...

they were developed in, whether they are open-source or proprietary, their support for natural language characters and conventions, and their assumptions about technical versus social control of

editing Editing is the process of selecting and preparing written language, written, Image editing, visual, Audio engineer, audible, or Film editing, cinematic material used by a person or an entity to convey a message or information. The editing p ...

History

The first generally recognized "wiki" application, WikiWikiWeb, was created by American computer programmer Ward Cunningham, 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 Version control (also known as revision control, source control, and source code management) is the software engineering practice of controlling, organizing, and tracking different versions in history of computer files; primarily source code t ...

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 Hypertext Markup Language (HTML) is the standard markup language for documents designed to be displayed in a web browser. It defines the content and structure of web content. It is often assisted by technologies such as Cascading Style Sheets ( ...

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

MediaWiki 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,mailarchive:wikipedia-l/2001-August/000382.html, Magnus Manske's announc ...

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

source code In computing, source code, or simply code or source, is a plain text computer program written in a programming language. A programmer writes the human readable source code to control the behavior of a computer. Since a computer, at base, only ...

with double square brackets. Page names thus did not interrupt the flow of English and could follow the 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, have also adopted wiki-like functionality.

Data compatibility

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

wiki markup A wiki ( ) is a form of hypertext publication on the internet which is Collaborative editing, collaboratively edited and managed by its audience directly through a web browser. A typical wiki contains multiple pages that can either be edit ...

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

knowledge base In computer science, a knowledge base (KB) is a set of sentences, each sentence given in a knowledge representation language, with interfaces to tell new sentences and to ask questions about what is known, where either of these interfaces migh ...

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 web content management system. It was originally created as a tool to publish blogs but has evolved to support publishing other web content, including more traditional websites, electronic mailing list, ma ...

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

Java Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 156.9 million people (including Madura) in mid 2024, proje ...

, 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 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, has few cross-markup conversion tools for migrating existing

s to it and no major engines use 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 wikis for

data management Data management comprises all disciplines related to handling data as a valuable resource, it is the practice of managing an organization's data so it can be analyzed for decision making. Concept The concept of data management emerged alongsi ...

by corporations and other organizations, and personal wikis, 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 types of wiki software are specifically designed for one of the usage types, while other types can be used for all three, but contain functionality, either in their 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.

is by far the most dominant software as it powers

Wikipedia Wikipedia is a free content, free Online content, online encyclopedia that is written and maintained by a community of volunteers, known as Wikipedians, through open collaboration and the wiki software MediaWiki. Founded by Jimmy Wales and La ...

, consistently and by a large margin, the most visited public wiki, it also powers many other public wikis as well. Other wiki engines used regularly for public wikis include MoinMoin and PmWiki, along with many others. Other Internet websites, based on wiki software, include encyclopedias such as Sensei's Library, Parlia, and WikiTree.

Enterprise wikis

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, Jive, Traction TeamPage and Notion. 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

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(since 2018),, Full Text Search as in Microsoft Teams, or Version Control. In addition, some open source wiki applications also describe themselves as enterprise solutions, including XWiki, Foswiki, TWiki, 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 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 Adobe Inc. ( ), formerly Adobe Systems Incorporated, is an American software, computer software company based in San Jose, California. It offers a wide range of programs from web design tools, photo manipulation and vector creation, through to ...

, Amazon.com,

Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, and Delaware General Corporation Law, incorporated in Delaware. Intel designs, manufactures, and sells computer compo ...

Microsoft Microsoft Corporation is an American multinational corporation and technology company, technology conglomerate headquartered in Redmond, Washington. Founded in 1975, the company became influential in the History of personal computers#The ear ...

, and the

United States intelligence community The United States Intelligence Community (IC) is a group of separate US federal government, U.S. federal government intelligence agencies and subordinate organizations that work to conduct Intelligence assessment, intelligence activities which ...

. 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 supervising the work of a Project team, team to achieve all project goals within the given constraints. This information is usually described in project initiation documentation, project documentation, crea ...

customer relationship management Customer relationship management (CRM) is a strategic process that organizations use to manage, analyze, and improve their interactions with customers. By leveraging data-driven insights, CRM helps businesses optimize communication, enhance cus ...

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 suit ...

, 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 (usually shortened to email; alternatively hyphenated e-mail) is a method of transmitting and receiving Digital media, digital messages using electronics, electronic devices over a computer network. It was conceived in the ...

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 PmWiki, Tomboy, and ConnectedText (now discontinued). Other, more general, wiki applications have components geared for individual users, including MoinMoin (which offers a "DesktopEdition"), and TiddlyWiki.

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 editor, either instead of or in addition to the wiki markup editing. Based on the atomic property of

database systems In computing, a database is an organized collection of Data (computing), data or a type of data store based on the use of a database management system (DBMS), the software that interacts with end users, Application software, applications, and ...

, any edit should be traced. On wiki software, the

chronology Chronology (from Latin , from Ancient Greek , , ; and , ''wikt:-logia, -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. It is also "the deter ...

of edits (e.g. published by Internet users) in any given article may be locally saved with a common .xml file extension by people having administrator rights.

Hosted application

There are a variety of wiki hosting services, otherwise known as wiki farms, that host users' wikis on a server. Some wiki software is only available in hosted form: PBworks, Wetpaint 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

, Socialtext,

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 Clipping (morphology), truncation of "weblog") is an informational website consisting of discrete, often informal diary-style text entries also known as posts. Posts are typically displayed in Reverse chronology, reverse chronologic ...

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 TWiki,

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

and XWiki, via plugins.

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:

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, Python, PHP or more generally any JSR223 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 The Semantic Web, sometimes known as Web 3.0, is an extension of the World Wide Web through standards set by the World Wide Web Consortium (W3C). The goal of the Semantic Web is to make Internet data machine-readable. To enable the encoding o ...

, or queried internally within the wiki. A wiki that allows such annotation is known as a semantic wiki. The current best-known semantic wiki software is Semantic MediaWiki, a plugin to MediaWiki.

Mobile access

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

mobile phone A mobile phone or cell phone is a portable telephone that allows users to make and receive calls over a radio frequency link while moving within a designated telephone service area, unlike fixed-location phones ( landline phones). This rad ...

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-ROM A CD-ROM (, compact disc read-only memory) is a type of read-only memory consisting of a pre-pressed optical compact disc that contains computer data storage, data computers can read, but not write or erase. Some CDs, called enhanced CDs, hold b ...

s 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 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, forming a peer-to-peer network of Node ...

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 engine (which can use the distributed revision control system Git 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. 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