A wiki ( ) is a

hypertext Hypertext is text displayed on a or other with references () to other text that the reader can immediately access. Hypertext documents are interconnected by hyperlinks, which are typically activated by a click, keypress set, or screen ...

publication collaboratively edited and managed by its own audience directly using a

web browser A web browser (commonly referred to as a browser) is application software Application software (app for short) is computing software designed to carry out a specific task other than one relating to the operation of the computer itself, typical ...

. A typical wiki contains multiple pages for the subjects or scope of the project and could be either open to the public or limited to use within an organization for maintaining its internal

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

. Wikis are enabled by

wiki software Wiki software (also known as a wiki engine or wiki application) is collaborative software that runs a wiki, which allows users to create and collaboratively edit pages or entries via a web browser. A wiki system is usually a web application that ...

, otherwise known as wiki engines. A wiki engine, being a form of a

content management system A content management system (CMS) is a 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. Ne ...

, differs from other

web-based A web application (or web app) is application software that runs on a web server, unlike computer-based software programs that are run locally on the operating system (OS) of the device. Web applications are accessed by the user through a web brow ...

systems such as

blog software A blog (a Clipping (morphology), 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 ...

, in that the content is created without any defined owner or leader, and wikis have little inherent structure, allowing structure to emerge according to the needs of the users. Wiki engines usually allow content to be written using a simplified

markup language #REDIRECT Markup language In computer text processing, a markup language is a system for annotation, annotating a document in a way that is Syntax (logic), syntactically distinguishable from the text, meaning when the document is processed for di ...

and sometimes edited with the help of a rich-text editor. There are dozens of different wiki engines in use, both standalone and part of other software, such as

bug tracking system A bug tracking system or defect tracking system is a software application that keeps track of reported software bug A software bug is an error, flaw or fault in a computer program or system A system is a group of Interaction, interacting ...

s. Some wiki engines 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 model ...

, whereas others are

proprietary {{Short pages monitor * "A wiki invites all users—not just experts—to edit any

page Page most commonly refers to: * Page (paper) A page is one side of a leaf A leaf (plural leaves) is the principal lateral appendage of the vascular plant plant stem, stem, usually borne above ground and specialized for photosynthesis. T ...

page

or to create new pages within the wiki Web site, using only a standard "plain-vanilla" Web browser without any extra add-ons." * "Wiki promotes meaningful topic associations between different pages by making page link creation intuitively easy and showing whether an intended target page exists or not." * "A wiki is ''not'' a carefully crafted site created by experts and professional writers and designed for casual visitors. Instead, it seeks to involve the typical visitor/user in an ongoing process of creation and collaboration that constantly changes the website landscape." A wiki enables communities of editors and contributors to write documents collaboratively. All that people require to contribute is a computer,

Internet The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a ''internetworking, network of networks'' that consist ...

access, a

, and a basic understanding of a simple markup language (e.g. MediaWiki markup language). A single page in a wiki website is referred to as a "wiki page", while the entire collection of pages, which are usually well-interconnected by

hyperlink In computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes and development of both computer hardware , hardware and so ...

s, is "the wiki". A wiki is essentially a

database In computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes and development of both computer hardware , hardware and sof ...

for creating, browsing, and searching through information. A wiki allows non-linear, evolving, complex, and networked text, while also allowing for editor argument, debate, and interaction regarding the content and formatting. A defining characteristic of wiki technology is the ease with which pages can be created and updated. Generally, there is no review by a moderator or

gatekeeper A gatekeeper is a person who controls access to something, for example via a city gate or bouncer, or more abstractly, controls who is granted access to a category or status. Gatekeepers assess who is "in or out," in the classic words of managem ...

before modifications are accepted and thus lead to changes on the website. Many wikis are open to alteration by the general public without requiring registration of

user User may refer to: Ancient Egyptian roles * User (ancient Egyptian official)User was an ancient Egypt Ancient Egypt was a civilization of Ancient history, ancient North Africa, concentrated along the lower reaches of the Nile, Nile Rive ...

accounts. Many edits can be made in real-time and appear almost instantly online, but this feature facilitates abuse of the system. Private wiki servers require

user authentication User may refer to: Ancient Egyptian roles * User (ancient Egyptian official)User was an ancient Egypt Ancient Egypt was a civilization of Ancient history, ancient North Africa, concentrated along the lower reaches of the Nile, Nile River ...

to edit pages, and sometimes even to read them. Maged N. Kamel Boulos, Cito Maramba, and Steve Wheeler write that the open wikis produce a process of

Social Darwinism Social Darwinism refers to various societal practices around the world and defined by scholars in Western Europe and North America in the 1870s that applied biological concepts of natural selection Natural selection is the differential ...

. "... because of the openness and rapidity that wiki pages can be edited, the pages undergo an evolutionary selection process, not unlike that which nature subjects to living organisms. 'Unfit' sentences and sections are ruthlessly culled, edited and replaced if they are not considered 'fit', which hopefully results in the evolution of a higher quality and more relevant page."

Editing

Source editing

Some wikis have an Edit button or link directly on the page being viewed if the user has permission to edit the page. This can lead to a text-based editing page where participants can structure and format wiki pages with a simplified markup language, sometimes known as wikitext, wiki markup or wikicode (it can also lead to 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 ...

editing page; see the paragraph after the table below). For example, starting lines of text with

asterisk The asterisk , from Late Latin , from Ancient Greek , ''asteriskos'', "little star", is a Typography, typographical symbol. It is so called because it resembles a conventional image of a star (heraldry), star. Computer scientists and mathem ...

s could create a

bulleted list

. The style and syntax of wikitexts can vary greatly among wiki implementations, some of which also allow

HTML tag 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 JavaScript. ...

Layout consistency

Wikis have favored plain-text editing, with fewer and simpler conventions than HTML for indicating style and structure. Although limiting access to HTML and

Cascading Style Sheets #REDIRECT CSS #REDIRECT CSS Cascading Style Sheets (CSS) is a style sheet language used for describing the presentation Introduction A presentation conveys information from a speaker to an audience. Presentations are typically demonst ...

(CSS) of wikis limits user ability to alter the structure and formatting of wiki content, there are some benefits. Limited access to CSS promotes consistency in the look and feel, and having

JavaScript JavaScript (), often abbreviated JS, is a programming language A programming language is a formal language In mathematics Mathematics (from Ancient Greek, Greek: ) includes the study of such topics as quantity (number theory), ma ...

disabled prevents a user from implementing code that may limit other users' access.

Basic syntax

Visual editing

Wikis can also make

editing available to users, usually through a

control that translates graphically entered formatting instructions into the corresponding

HTML tags An HTML element is a type of HTML (Hypertext Markup Language) document component, one of several types of HTML nodes (there are also text nodes, comment nodes and others). HTML document is composed of a Tree structure, tree of simple HTML Node ...

or wikitext. In those implementations, the markup of a newly edited, marked-up version of the page is generated and submitted to the server transparently, shielding the user from this technical detail. An example of this is the

VisualEditor VisualEditor (VE) is an online rich-text editor for MediaWiki-powered wikis that provides a direct visual way to edit pages based on the WYSIWYG, "what you see is what you get" principle. It was developed by the Wikimedia Foundation in partners ...

on Wikipedia. WYSIWYG controls do not, however, always provide all the features available in wikitext, and some users prefer not to use a WYSIWYG editor. Hence, many of these sites offer some means to edit the wikitext directly.

Version history

Some wikis keep a record of changes made to wiki pages; often, every version of the page is stored. This means that authors can revert to an older version of the page should it be necessary because a mistake has been made, such as the content accidentally being deleted or the page has been vandalized to include offensive or malicious text or other inappropriate content.

Edit summary

Many wiki implementations, such as

MediaWiki MediaWiki is a free and open-source Free and open-source software (FOSS) is software that is both free software and open-source software where anyone is free software license, freely licensed to use, copy, study, and change the softwa ...

, the software that powers Wikipedia, allow users to supply an ''edit summary'' when they edit a page. This is a short piece of text summarizing the changes they have made (e.g. "Corrected grammar," or "Fixed formatting in table."). It is not inserted into the article's main text but is stored along with that revision of the page, allowing users to explain what has been done and why. This is similar to a log message when making changes in a revision-control system. This enables other users to see which changes have been made by whom and why, often in a list of summaries, dates and other short, relevant content, a list which is called a "log" or "history."

Navigation

Within the text of most pages, there are usually many

links to other pages within the wiki. This form of non-linear navigation is more "native" to a wiki than structured/formalized navigation schemes. Users can also create any number of index or table-of-contents pages, with hierarchical categorization or whatever form of organization they like. These may be challenging to maintain "by hand", as multiple authors and users may create and delete pages in an

ad hoc Ad hoc is a Latin phrase __NOTOC__ This is a list of Wikipedia articles of Latin phrases and their translation into English. To view all phrases on a single, lengthy document, see: * List of Latin phrases (full) The list also is divided alpha ...

ad hoc

, unorganized manner. Wikis can provide one or more ways to categorize or tag pages to support the maintenance of such index pages. Some wikis, including the original, have a

backlink A backlink for a given web resource is a link Link or Links may refer to: Places * Link, West Virginia, an unincorporated community in the US * Link River, Klamath Falls, Oregon, US People with the name * Link (singer) (Lincoln Browder, b ...

feature, which displays all pages that link to a given page. It is also typically possible in a wiki to create links to pages that do not yet exist, as a way to invite others to share what they know about a subject new to the wiki. Wiki users can typically "tag" pages with categories or keywords, to make it easier for other users to find the article. For example, a user creating a new article on cold-weather biking might "tag" this page under the categories of commuting, winter sports and bicycling. This would make it easier for other users to find the article.

Linking and creating pages

Links are created using a specific syntax, the so-called "link pattern". Originally, most wikis used

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, indicating the separation of words with a single capitalized ...

to name pages and create links. These are produced by capitalizing words in a phrase and removing the spaces between them (the word "CamelCase" is itself an example). While CamelCase makes linking easy, it also leads to links in a form that deviates from the standard spelling. To link to a page with a single-word title, one must abnormally capitalize one of the letters in the word (e.g. "WiKi" instead of "Wiki"). CamelCase-based wikis are instantly recognizable because they have many links with names such as "TableOfContents" and "BeginnerQuestions." a wiki can render the visible anchor of such links "pretty" by reinserting spaces, and possibly also reverting to lower case. This reprocessing of the link to improve the readability of the anchor is, however, limited by the loss of capitalization information caused by CamelCase reversal. For example, "RichardWagner" should be rendered as "Richard Wagner", whereas "PopularMusic" should be rendered as "popular music". There is no easy way to determine which

capital letter Letter case is the distinction between the letters Letter, letters, or literature may refer to: Characters typeface * Letter (alphabet) A letter is a segmental symbol A symbol is a mark, sign, or word that indicates, signifies, or ...

s should remain capitalized. As a result, many wikis now have "free linking" using brackets, and some disable CamelCase by default.

Searching

Most wikis offer at least a title

search Searching or search may refer to: Computing technology * Search algorithm In computer science, a search algorithm is an algorithm (typically involving a multitude of other, more specific algorithms ) which solves a search problem. Search al ...

, and sometimes a

full-text search In text retrieval, full-text search refers to techniques for searching a single computer A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations automatically. Modern computers can perform ...

. The scalability of the search depends on whether the wiki engine uses a database. Some wikis, such as

PmWiki PmWiki is wiki software Wiki software (also known as a wiki engine or wiki application) is collaborative software that runs a wiki, which allows users to create and collaboratively edit pages or entries via a web browser. A wiki system is usual ...

PmWiki

, use

flat file Image:Flat File Model.svg, 280px, Example of a flat file modelbyte.html" ;"title="hex dump of the 318 byte">hex dump of the 318 byte Wikipedia favicon, or . The first column numerates the line's starting address, while the * indicates repetition ...

s. MediaWiki's first versions used flat files, but it was rewritten by

Lee Daniel Crocker 240px, Lee Daniel Crocker at Internet Archive, 2008 Lee Daniel Crocker (born July 3, 1963) is an American computer programmer A computer programmer, sometimes called a software developer, a programmer or more recently a coder (especially in ...

in the early 2000s (decade) to be a database application. Indexed database access is necessary for high speed searches on large wikis. Alternatively, external

search engines A search engine is a software system that is designed to carry out web searches (Internet searches), which means to search the World Wide Web upright=1.35, A global map of the web index for countries in 2014 The World Wide Web (WWW), ...

such as

Google Search Google Search (also known simply as Google), is a search engine A search engine is a software system A software system is a system of intercommunicating software component, components based on forming part of a computer system (a combin ...

can sometimes be used on wikis with limited searching functions to obtain more precise results.

History

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

was the first wiki. Ward Cunningham started developing WikiWikiWeb in Portland, Oregon, in 1994, and installed it on the

Internet domain A domain name is an identification string that defines a realm of administrative autonomy, authority or control within the Internet The Internet (Capitalization of Internet, or internet) is the global system of interconnected compute ...

c2.com The WikiWikiWeb is the first wiki A wiki ( ) is a hypertext Douglas Engelbart in 2009, at the 40th anniversary celebrations of "The Mother of All Demos" in San Francisco, a 90-minute 1968 presentation of the NLS (computer sy ...

on March 25, 1995. It was named by Cunningham, who remembered a

Honolulu International Airport Daniel K. Inouye International Airport , also known as Honolulu International Airport, is the principal aviation gateway of the City and County of Honolulu on Oahu in the State of Hawaii.

counter employee telling him to take the "

Wiki Wiki Shuttle The Wiki Wiki Shuttle (''lit. Quick Quick Shuttle'') is a free public transport, free Public transport, shuttle bus service at Daniel K. Inouye International Airport in Honolulu, Hawaii. Shuttles run between 6:00 am and 10:00 pm Hawaii–Aleutian ...

" bus that runs between the airport's terminals. According to Cunningham, "I chose wiki-wiki as an alliterative substitute for 'quick' and thereby avoided naming this stuff quick-web." Cunningham was, in part, inspired by the

Apple An apple is an edible fruit In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this fie ...

HyperCard HyperCard is a software application Application software (app for short) is computing software designed to carry out a specific task other than one relating to the operation of the computer itself, typically to be used by end-users. Examples o ...

, which he had used. HyperCard, however, was single-user. Apple had designed a system allowing users to create virtual "card stacks" supporting links among the various cards. Cunningham developed

Vannevar Bush Vannevar Bush ( ; March 11, 1890 – June 28, 1974) was an American engineer, inventor and science administrator, who during World War II, World War II headed the U.S. Office of Scientific Research and Development (OSRD), through which almo ...

's ideas by allowing users to "comment on and change one another's text." Cunningham says his goals were to link together people's experiences to create a new literature to document programming

patterns A pattern is a regularity in the world, in human-made design, or in abstract ideas. As such, the elements of a pattern repeat in a predictable manner. A geometric pattern is a kind of pattern formed of geometric Geometry (from the grc, ...

, and to harness people's natural desire to talk and tell stories with a technology that would feel comfortable to those not used to "authoring". Wikipedia became the most famous wiki site, launched in January 2001 and entering the top ten most popular websites in 2007. In the early 2000s (decade), wikis were increasingly adopted in enterprise as collaborative software. Common uses included project communication, intranets, and documentation, initially for technical users. Some companies use wikis as their only collaborative software and as a replacement for static intranets, and some schools and universities use wikis to enhance

group learning

. There may be greater use of wikis behind

firewalls Firewall may refer to: * Firewall (computing), a technological barrier designed to prevent unauthorized or unwanted communications between computer networks or hosts * Firewall (construction), a barrier inside a building, designed to limit the sprea ...

than on the public Internet. On March 15, 2007, the word ''wiki'' was listed in the online ''

Oxford English Dictionary The ''Oxford English Dictionary'' (''OED'') is the principal historical dictionary A historical dictionary or dictionary on historical principles is a dictionary which deals not only with the latterday meanings of words but also the historica ...

''.

Alternative definitions

In the late 1990s and early 2000s, the word "wiki" was used to refer to both user-editable websites and the software that powers them; the latter definition is still occasionally in use. Wiki inventor Ward Cunningham wrote in 2014 that the word "wiki" should not be used to refer to a single website, but rather to a mass of user-editable pages or sites so that a single website is not "a wiki" but "an instance of wiki". He wrote that the concept of wiki federation, in which the same content can be hosted and edited in more than one location in a manner similar to

distributed version control In software development Software development is the process of conceiving, specifying, designing, programming, documenting, testing, and bug fixing involved in creating and maintaining applications Application may refer to: Mathematics and ...

, meant that the concept of a single discrete "wiki" no longer made sense.

Implementations

Wiki software A 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 earlies ...

is a type of

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 system, allowing web pages to be created and edited using a common web browser. It may be implemented as a series of scripts behind an existing

web server A web server is computer A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations automatically. Modern computers can perform generic sets of operations known as Computer program, pr ...

or as a standalone

application server An application server is a server that hosts applications. Application server frameworks are software framework In computer programming, a software framework is an abstraction (computer science), abstraction in which software providing generic fu ...

that runs on one or more web servers. The content is stored in a

file system In computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes and development of both computer hardware , hardware and soft ...

, and changes to the content are stored in a

relational database A relational database is a digital database In , a database is an organized collection of stored and accessed electronically from a . Where databases are more complex they are often developed using formal techniques. The (DBMS) is the tha ...

management system. A commonly implemented software package is

, which runs Wikipedia. Alternatively, personal wikis run as a standalone application on a single computer. Wikis can also be created on a " wiki farm", where the server-side software is implemented by the wiki farm owner. Some wiki farms can also make private, password-protected wikis. Free wiki farms generally contain advertising on every page. For more information, see Comparison of wiki hosting services.

Trust and security

Controlling changes

Wikis are generally designed with the philosophy of making it easy to correct mistakes, rather than making it difficult to make them. Thus, while wikis are very open, they provide a means to verify the validity of recent additions to the body of pages. The most prominent, on almost every wiki, is the "Recent Changes" page—a specific list showing recent edits, or a list of edits made within a given time frame. Some wikis can filter the list to remove minor edits and edits made by automatic importing scripts ("

bots The British Overseas Territories (BOTs), also known as United Kingdom Overseas Territories (UKOTs), are fourteen dependent territory, territories all with a constitutional and historical link with the United Kingdom. They are remnants of the B ...

"). From the change log, other functions are accessible in most wikis: the revision history shows previous page versions and the

diff In computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes and development of both computer hardware , hardware and sof ...

diff

feature highlights the changes between two revisions. Using the revision history, an editor can view and restore a previous version of the article. This gives great power to the author to eliminate edits. The diff feature can be used to decide whether or not this is necessary. A regular wiki user can view the diff of an edit listed on the "Recent Changes" page and, if it is an unacceptable edit, consult the history, restoring a previous revision; this process is more or less streamlined, depending on the wiki software used. In case unacceptable edits are missed on the "recent changes" page, some wiki engines provide additional content control. It can be monitored to ensure that a page, or a set of pages, keeps its quality. A person willing to maintain pages will be warned of modifications to the pages, allowing them to verify the validity of new editions quickly. This can be seen as a very pro-author and anti-editor feature. A watchlist is a common implementation of this. Some wikis also implement "patrolled revisions", in which editors with the requisite credentials can mark some edits as not vandalism. A "flagged revisions" system can prevent edits from going live until they have been reviewed.

Trustworthiness and reliability of content

Critics of publicly editable wiki systems argue that these systems could be easily tampered with by malicious individuals ("vandals") or even by well-meaning but unskilled users who introduce errors into the content, while proponents maintain that the community of users can catch such malicious or erroneous content and correct it.

Lars AronssonImage:LA2-IMG 4068.jpg, Lars Aronsson at Wikimania 2016 Lars Erik Aronsson (born 19 March 1966 in Örebro, Sweden) is a Swedes, Swedish programmer and consultant, and the founder of two Swedish web sites: the free electronic book archive Project Run ...

, a data systems specialist, summarizes the controversy as follows: "Most people when they first learn about the wiki concept, assume that a Web site that can be edited by anybody would soon be rendered useless by destructive input. It sounds like offering free spray cans next to a grey concrete wall. The only likely outcome would be ugly

graffiti Graffiti (both singular and plural; the singular ''graffito'' is rarely used except in archeology) is a type of art genre that means writing or drawings made on a wall or other surface, usually without permission and within public view. Graf ...

and simple tagging and many artistic efforts would not be long lived. Still, it seems to work very well." High editorial standards in medicine and health sciences articles, in which users typically use peer-reviewed journals or university textbooks as sources, have led to the idea of expert-moderated wikis. Some wikis allow one to link to specific versions of articles, which 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. Noveck points out that "participants are accredited by members of the wiki community, who have a vested interest in preserving the quality of the work product, on the basis of their ongoing participation." On controversial topics that have been subject to disruptive editing, a wiki author may restrict editing to registered users.

Security

The open philosophy of wiki – allowing anyone to edit content – does not ensure that every editor's intentions are well-mannered. For example,

vandalism Vandalism is the action involving deliberate destruction of or damage to public or private property. The term includes property damage Property damage ( cf. criminal damage in England and Wales) is damage or destruction of real Real may r ...

(changing wiki content to something offensive, adding nonsense, maliciously removing encyclopedic content, or deliberately adding incorrect information, such as

hoax A hoax is a falsehood deliberately fabricated to masquerade as the truth. It is distinguishable from errors in observation or judgment, rumor A rumour (British English), or rumor (American English; American and British English spelling diffe ...

hoax

information) can be a major problem. On larger wiki sites, such as those run by the

Wikimedia Foundation Wikimedia Foundation, Inc. (WMF, or simply Wikimedia) is an American foundation headquartered in San Francisco, California San Francisco (; Spanish language, Spanish for "Francis of Assisi, Saint Francis"), officially the City and ...

, vandalism ''can ''go unnoticed for some period of time. Wikis, because of their open nature, are susceptible to intentional disruption, known as "

trolling In Internet slang, a troll is a person who starts Flamewars, flame wars or intentionally upsets people on the Internet. This is typically done by posting inflammatory and digressive, wikt:extraneous#Adjective, extraneous, or off-topic messages ...

". Wikis tend to take a '' soft-security'' approach to the problem of vandalism, making damage easy to undo rather than attempting to prevent damage. Larger wikis often employ sophisticated methods, such as bots that automatically identify and revert vandalism and JavaScript enhancements that show characters that have been added in each edit. In this way, vandalism can be limited to just "minor vandalism" or "sneaky vandalism", where the characters added/eliminated are so few that bots do not identify them and users do not pay much attention to them. An example of a bot that reverts vandalism on Wikipedia is ClueBot NG. ClueBot NG can revert edits, often within minutes, if not seconds. The bot uses

machine learning Machine learning (ML) is the study of computer algorithms that can improve automatically through experience and by the use of data. It is seen as a part of artificial intelligence. Machine learning algorithms build a model based on sample data ...

in lieu of

heuristics A heuristic (; ), or heuristic technique, is any approach to problem solving Problem solving consists of using generic or ad hoc Ad hoc is a Latin phrase __NOTOC__ This is a list of Wikipedia articles of Latin phrases and their transla ...

. The amount of vandalism a wiki receives depends on how open the wiki is. For instance, some wikis allow unregistered users, identified by their

IP address An Internet Protocol address (IP address) is a numerical label such as that is connected to a computer network A computer network is a set of s sharing resources located on or provided by . The computers use common s over to communi ...

es, to edit content, while others limit this function to just registered users. Edit wars can also occur as users repetitively revert a page to the version they favor. In some cases, editors with opposing views of which content should appear or what formatting style should be used will change and re-change each other's edits. This results in the page being "unstable" from a general user's perspective, because each time a general user comes to the page, it may look different. Some wiki software allows an administrator to stop such edit wars by locking a page from further editing until a decision has been made on what version of the page would be most appropriate. Some wikis are in a better position than others to control behavior due to governance structures existing outside the wiki. For instance, a college teacher can create incentives for students to behave themselves on a class wiki they administer by limiting editing to logged-in users and pointing out that all contributions can be traced back to the contributors. Bad behavior can then be dealt with under university policies.

Potential malware vector

Malware Malware (a portmanteau for malicious software) is any software intentionally designed to cause disruption to a computer, server (computing), server, Client (computing), client, or computer network, leak private information, gain unauthorized acc ...

Malware

can also be a problem for wikis, as users can add links to sites hosting malicious code. For example, a German Wikipedia article about the

Blaster Worm Blaster (also known as Lovsan, Lovesan, or MSBlast) was a computer worm that spread on computers running operating systems Windows XP and Windows 2000 during August 2003. The worm was first noticed and started spreading on August 11, 2003. The ra ...

was edited to include a hyperlink to a malicious website. Users of vulnerable Microsoft Windows systems who followed the link would be infected. A countermeasure is the use of software that prevents users from saving an edit that contains a link to a site listed on a

blacklist Blacklisting is the action of a group or authority, compiling a blacklist (or black list) of people, countries or other entities to be avoided or distrusted as being deemed unacceptable to those making the list. If someone is on a blacklist, t ...

of malicious sites.

Communities

Applications

The English Wikipedia has the largest user base among wikis on the

World Wide Web The World Wide Web (WWW), commonly known as the Web, is an information system An information system (IS) is a formal, sociotechnical Sociotechnical systems (STS) in organizational development is an approach to complex organizational ...

and ranks in the top 10 among all Web sites in terms of traffic. Other large wikis include the

Memory Alpha Memory Alpha is a wiki A wiki ( ) is a hypertext publication Collaborative editing, collaboratively edited and managed by its own audience directly using a web browser. A typical wiki contains multiple pages for the subjects or scope of t ...

Wikivoyage Wikivoyage is a free web-based travel guide for travel destinations and travel topics written by volunteer authors. It is a sister project of Wikipedia and supported and hosted by the same non-profit Wikimedia Foundation The Wikimedia Foun ...

, and Susning.nu, a Swedish-language knowledge base.

Medical Medicine is the science Science () is a systematic enterprise that builds and organizes knowledge Knowledge is a familiarity, awareness, or understanding of someone or something, such as facts ( descriptive knowledge), skills (proced ...

and health-related wiki examples include Ganfyd, an online collaborative medical reference that is edited by medical professionals and invited non-medical experts. Many wiki

communities A community is a social unit (a group of living things) with commonality such as norms, religion Religion is a social system, social-cultural system of designated religious behaviour, behaviors and practices, morality, morals, beliefs, wor ...

are private, particularly within enterprises. They are often used as internal documentation for in-house systems and applications. Some companies use wikis to allow customers to help produce software documentation. A study of corporate wiki users found that they could be divided into "synthesizers" and "adders" of content. Synthesizers' frequency of contribution was affected more by their impact on other wiki users, while adders' contribution frequency was affected more by being able to accomplish their immediate work. From a study of thousands of wiki deployments, Jonathan Grudin concluded careful stakeholder analysis and education are crucial to successful wiki deployment. In 2005, the Gartner Group, noting the increasing popularity of wikis, estimated that they would become mainstream collaboration tools in at least 50% of companies by 2009. Wikis can be used for

project management Project management is the process of leading the work of a team A team is a group of individuals (human or non-human) working together to achieve their goal A goal is an idea In philosophy Philosophy (from , ) is the study o ...

. Wikis have also been used in the academic community for sharing and dissemination of information across institutional and international boundaries. In those settings, they have been found useful for collaboration on

grant writing Grant writing is the practice of completing an application process for a financial grant provided by an institution such as a government department, corporation, foundation, or trust. Such application processes are often referred to as either a ...

strategic planning Strategic planning is an organization An organization, or organisation (Commonwealth English The use of the English language English is a of the , originally spoken by the inhabitants of . It is named after the , one of th ...

, departmental documentation, and committee work. In the mid-2000s, the increasing trend among industries toward collaboration placed a heavier impetus upon educators to make students proficient in collaborative work, inspiring even greater interest in wikis being used in the classroom. Wikis have found some use within the legal profession and within the government. Examples include the

Central Intelligence Agency The Central Intelligence Agency (CIA; ), known informally as the Agency and the Company, is a civilian foreign intelligence service of the federal government of the United States The federal government of the United States (U.S. fed ...

Intellipedia Intellipedia is an online system for collaborative data sharing used by the United States Intelligence Community (IC). It was established as a pilot project in late 2005 and formally announced in April 2006. Intellipedia consists of three wi ...

, designed to share and collect

intelligence Intelligence has been defined in many ways: the capacity for abstraction, logic, understanding, self-awareness, learning, emotional knowledge, reasoning, planning, creativity, critical thinking, and problem-solving. More generally, it can be des ...

, DKospedia, which was used by the

American Civil Liberties Union The American Civil Liberties Union (ACLU) is a nonprofit organization A nonprofit organization (NPO), also known as a non-business entity, not-for-profit organization, or nonprofit institution, is a legal entity organized and operated for ...

to assist with review of documents about the internment of detainees in

Guantánamo Bay Guantánamo Bay ( es, Bahía de Guantánamo) is a bay in Guantánamo Province at the southeastern end of Cuba. It is the largest harbor on the south side of the island and it is surrounded by steep hills which create an enclave that is cut off ...

; and the wiki of the

United States Court of Appeals for the Seventh Circuit The United States Court of Appeals for the Seventh Circuit (in case citation Case citation is a system used by legal professionals to identify past court case A legal case is in a general sense a dispute between opposing parties which may b ...

, used to post court rules and allow practitioners to comment and ask questions. The

United States Patent and Trademark Office The United States Patent and Trademark Office (USPTO) is an agency in the U.S. Department of Commerce that issues patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using ...

operates Peer-to-Patent, a wiki to allow the public to collaborate on finding

prior art Prior art (also known as state of the art or background art) is a concept in patent law used to determine the patentability of an invention, in particular whether an invention meets the Novelty (patent), novelty and the inventive step or non-obvio ...

relevant to the examination of pending patent applications.

Queens Queens is a borough of New York City, coextensive with Queens County, in the U.S. state of New York. It is the largest borough of New York City New York City (NYC), often simply called New York, is the List of United States cities by po ...

Queens

, New York has used a wiki to allow citizens to collaborate on the design and planning of a local park.

Cornell Law School Cornell Law School is the law school of Cornell University, a private university, private Ivy League university in Ithaca, New York. One of the five Ivy League law schools, it offers four law degree, law degree programs, Juris Doctor, JD, Master ...

founded a wiki-based legal dictionary called Wex, whose growth has been hampered by restrictions on who can edit. In academic contexts, wikis have also been used as project collaboration and research support systems.

City wikis

A city wiki (or local wiki) is a wiki used as a

and

social network A social network is a social structure made up of a set of social actors (such as individuals or organizations), sets of Dyad (sociology), dyadic ties, and other Social relation, social interactions between actors. The social network perspectiv ...

for a specific

geographical Geography (from Greek Greek may refer to: Greece Anything of, from, or related to Greece Greece ( el, Ελλάδα, , ), officially the Hellenic Republic, is a country located in Southeast Europe. Its population is approximately 10. ...

locale. The term 'city wiki' or its foreign language equivalent (e.g. German 'Stadtwiki') is sometimes also used for wikis that cover not just a city, but a small town or an entire region. A city wiki contains information about specific instances of things, ideas, people and places. Much of this information might not be appropriate for

encyclopedia An encyclopedia (American English), encyclopædia (archaic spelling), or encyclopaedia (British English) is a reference work or compendium providing summaries of knowledge either from all branches or from a particular field or discipline. ...

s such as Wikipedia (e.g. articles on every retail outlet in a town), but might be appropriate for a wiki with more localized content and viewers. A city wiki could also contain information about the following subjects, that may or may not be appropriate for a general knowledge wiki, such as: * Details of public establishments such as public houses, bars, accommodation or social centers * Owner name, opening hours and statistics for a specific shop * Statistical information about a specific road in a city * Flavors of ice cream served at a local ice cream parlor * A biography of a local mayor and other persons

WikiNodes

WikiNodes are pages on wikis that describe related wikis. They are usually organized as neighbors and delegates. A ''neighbor'' wiki is simply a wiki that may discuss similar content or may otherwise be of interest. A ''delegate'' wiki is a wiki that agrees to have certain content delegated to that wiki. One way of finding a wiki on a specific subject is to follow the wiki-node network from wiki to wiki; another is to take a Wiki "bus tour", for example: .

Participants

The four basic types of users who participate in wikis are reader, author, wiki administrator and system administrator. The system administrator is responsible for the installation and maintenance of the wiki engine and the container web server. The wiki administrator maintains wiki content and is provided additional functions about pages (e.g. page protection and deletion), and can adjust users' access rights by, for instance, blocking them from editing.

Growth factors

A study of several hundred wikis showed that a relatively high number of administrators for a given content size is likely to reduce growth; that access controls restricting editing to registered users tends to reduce growth; that a lack of such access controls tends to fuel new user registration; and that higher administration ratios (i.e. admins/user) have no significant effect on content or population growth.

Conferences

Active conferences and meetings about wiki-related topics include: * Atlassian Summit, an annual conference for users of

Atlassian Atlassian Corporation Plc () is an Australian software company that develops products for software development, software developers, project management, project managers and other software development teams. History Mike Cannon-Brookes and S ...

software, including

Confluence In geography Geography (from Greek Greek may refer to: Greece Anything of, from, or related to Greece Greece ( el, Ελλάδα, , ), officially the Hellenic Republic, is a country located in Southeast Europe. Its population is ...

. * OpenSym (called WikiSym until 2014), an

academic conference An academic conference or scientific conference (also symposium, workshop, or meeting) is an event Event may refer to: Gatherings of people * Ceremony A ceremony (, ) is a unified ritual A ritual is a sequence of activities involving gestu ...

dedicated to research about wikis and open collaboration. * SMWCon, a bi-annual conference for users and developers of

Semantic MediaWiki Semantic MediaWiki (SMW) is an extension to MediaWiki MediaWiki is a Free and open-source software, free and open-source wiki software. It was developed for use on Wikipedia in 2002, and given the name "MediaWiki" in 2003. It remains in us ...

. * TikiFest, a frequently held meeting for users and developers of

Tiki Wiki CMS Groupware Tiki Wiki CMS Groupware or simply Tiki, originally known as TikiWiki, is a free and open source Wiki A wiki ( ) is a hypertext publication Collaborative editing, collaboratively edited and managed by its own audience directly using a web br ...

. *

Wikimania Wikimania is the official annual conference of the Wikimedia Foundation. Topics of presentations and discussions include Wikimedia projects such as Wikipedia, other wikis, open-source software, free knowledge and free content, and social and ...

, an annual conference dedicated to the research and practice of

projects like Wikipedia. Former wiki-related events include: * RecentChangesCamp (2006–2012), an

unconference An unconference is a participant-driven meeting. The term "unconference" has been applied, or self-applied, to a wide range of gatherings that try to avoid hierarchical aspects of a conventional conference A conference is a meeting of people wh ...

on wiki-related topics. * RegioWikiCamp (2009–2013), a semi-annual unconference on "regiowikis", or wikis on cities and other geographic areas.

Legal environment

Joint authorship of articles, in which different users participate in correcting, editing, and compiling the finished product, can also cause editors to become

tenants in common In property law, a concurrent estate or co-tenancy is any of various ways in which property Property (''latin: Res Privata'') in the Abstract and concrete, abstract is what belongs to or with something, whether as an attribute or as a compon ...

of the copyright, making it impossible to republish without permission of all co-owners, some of whose identities may be unknown due to pseudonymous or anonymous editing. Where persons contribute to a

collective work A collective work is a work that contains the works of several authors assembled and published under the direction of one natural or legal person who owns the copyright Copyright is a type of intellectual property Intellectual propert ...

such as an encyclopedia, there is, however, no joint ownership if the contributions are separate and distinguishable. Despite most wikis' tracking of individual contributions, the action of contributing to a wiki page is still arguably one of jointly correcting, editing, or compiling, which would give rise to joint ownership. Some copyright issues can be alleviated through the use of an

open content Free content, libre content, or free information is any kind of functional work, work of art, or other creative Content (media and publishing), content that meets the definition of a Definition of Free Cultural Works, free cultural work. De ...

license. Version 2 of the

GNU Free Documentation License The GNU Free Documentation License (GNU FDL or simply GFDL) is a copyleft Copyleft is the practice of granting the right to freely distribute and modify with the requirement that the same rights be preserved in derivative works created fr ...

includes a specific provision for wiki relicensing;

Creative Commons Creative Commons (CC) is an American non-profit organization A nonprofit organization (NPO), also known as a non-business entity, not-for-profit organization, or nonprofit institution, is a legal entity organized and operated for a collect ...

licenses are also popular. When no license is specified, an implied license to read and add content to a wiki may be deemed to exist on the grounds of business necessity and the inherent nature of a wiki, although the legal basis for such an implied license may not exist in all circumstances. Wikis and their users can be held liable for certain activities that occur on the wiki. If a wiki owner displays indifference and forgoes controls (such as banning copyright infringers) that he could have exercised to stop copyright infringement, he may be deemed to have authorized infringement, especially if the wiki is primarily used to infringe copyrights or obtains a direct financial benefit, such as advertising revenue, from infringing activities. In the United States, wikis may benefit from

Section 230 of the Communications Decency Act Section 230 is a section of Title 47 of the United States CodeTitle 47 of the United States Code defines the role and structure of the Federal Communications Commission The Federal Communications Commission (FCC) is an Independent agencies of ...

, which protects sites that engage in "

Good Samaritan In most contexts, the concept of good denotes the conduct that should be preferred when posed with a choice between possible actions. Good is generally considered to be the opposite of evil Evil, in a general sense, is defined by what it ...

" policing of harmful material, with no requirement on the quality or quantity of such self-policing. It has also been argued, however, that a wiki's enforcement of certain rules, such as anti-bias, verifiability, reliable sourcing, and no-original-research policies, could pose legal risks. When

defamation Defamation (also known as calumny, vilification, libel, slander, or traducement) is the oral or written communication of a false statement about another that unjustly harms their reputation and usually constitutes a tort A tort, in commo ...

occurs on a wiki, theoretically, all users of the wiki can be held liable, because any of them had the ability to remove or amend the defamatory material from the "publication." It remains to be seen whether wikis will be regarded as more akin to an

internet service provider An Internet service provider (ISP) is an organization that provides a myriad of services for accessing, using, or participating in the Internet The Internet (or internet) is the global system of interconnected computer networks that ...

, which is generally not held liable due to its lack of control over publications' contents, than a publisher. It has been recommended that trademark owners monitor what information is presented about their trademarks on wikis, since courts may use such content as evidence pertaining to public perceptions. Joshua Jarvis notes, "Once misinformation is identified, the trademark owner can simply edit the entry."

Notes

References

External links

*
''Exploring with Wiki''
an interview with

Ward Cunningham Howard G. Cunningham (born May 26, 1949) is an American computer programmer A computer programmer, sometimes called a software developer, a programmer or more recently a coder (especially in more informal contexts), is a person who creates ...

by Bill Verners * WikiIndex an
WikiApiary
directories of wikis
WikiMatrix
a website for comparing wiki software and hosts
WikiTeam
a volunteer group to preserve wikis associated with

Archive Team The Archive Team is a group dedicated to digital preservation and web archiving that was co-founded by Jason Scott in 2009. Its primary focus is the copying and preservation of content housed by at-risk online services. Some of its projects inc ...

* Murphy, Paula (April 2006)
Topsy-turvy World of Wiki
University of California.
Ward Cunningham's correspondence with etymologists
{{Authority control Wikis, Hawaiian words and phrases Hypertext Self-organization Social information processing Articles containing video clips