Wiki

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A wiki (IPA: [ˈwɪ.kiː] or [ˈwiː.kiː]^[1]) is a website that allows visitors to add, remove, edit and change content, typically without the need for registration. It also allows for linking among any number of pages. This ease of interaction and operation makes a wiki an effective tool for mass collaborative authoring. The term wiki also can refer to the collaborative software itself (wiki engine) that facilitates the operation of such a site, or to certain specific wiki sites, including the computer science site (the original wiki) WikiWikiWeb and online encyclopedias such as Wikipedia.

Contents 1 History 2 Key characteristics 2.1 Pages and editing 2.2 Linking and creating pages 2.3 Searching 2.4 Server-side versus client-side wiki 2.5 Web-based versus peer-to-peer 3 Controlling changes 4 Vandalism 5 Wiki communities 6 Wikis and content management systems 7 See also 8 Notes 9 References 10 External links

History

WikiWikiWeb was the first such site to be called a wiki. Ward Cunningham started developing WikiWikiWeb in 1994 and installed it on Internet domain c2.com on March 25, 1995. It was named by Cunningham, who remembered a Honolulu International Airport counter employee telling him to take the so-called "Wiki Wiki" Chance RT-52 shuttle bus line 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."^[1][2] Wiki Wiki is a reduplication of wiki, a Hawaiian-language word for fast. The word wiki is a shorter form of wiki wiki (IPA /wiːkiː wiːkiː/).

The word is sometimes interpreted as the backronym for what I know is, which describes the knowledge contribution, storage, and the exchange function.^[3]

According to Cunningham, the idea of "Wiki" can be traced back to a HyperCard stack he wrote in the late 1980s.^[4] In the early 2000s, wikis were increasingly adopted in the enterprise as collaborative software. Common uses included project communication, intranets, and documentation, initially for technical users. Today some companies use wikis as their only collaborative software and as a replacement for static intranets. There may be greater use of wikis behind firewalls than on the public Internet.

On March 15, 2007, wiki entered the Oxford English Dictionary Online.^{[5] [6]}

Key characteristics

A wiki enables documents to be written very collaboratively, in a simple markup language using a web browser. A single page in a wiki is referred to as a "wiki page", while the entire body of pages, which are usually highly interconnected via hyperlinks, is "the wiki". A wiki is actually a very simple, easy-to-use user-maintained database for creating, browsing and searching information.

A defining characteristic of wiki technology is the ease with which pages can be created and updated. Generally, there is no review before modifications are accepted. Many wikis are open to the general public without the need to register any user account. Sometimes session log-in is requested to acquire a "wiki-signature" cookie for autosigning edits. Many edits, however, can be made in real-time, and appear almost instantaneously online. This can lead to abuse of the system. Private wiki servers require user authentication to edit, sometimes even to read pages.

Pages and editing

The source format, sometimes known as "wikitext'", is augmented with a simplified markup language to indicate various structural and visual conventions. An often used example of one such convention is to start a line of text with an asterisk ("*") in order to mark it as an item in a bulleted list. Style and syntax can vary a great deal among implementations, some of which also allow HTML tags.

The reasoning behind this design is that HTML, with its many cryptic tags, is not especially human-readable. Making typical HTML source visible makes the actual text content very hard to read and edit for most users. It is therefore better to promote plain-text editing with a few simple conventions for structure and style.

Many implementations (for example Mediawiki) allow users to supply an "edit summary" along with their change. This is a short piece of text (usually one line) summarising the changes made that is not inserted into the article, but is stored along with that revision, allowing users to explain what has been done and why; similar to a log message when committing changes to a revision control system.

It is somewhat beneficial that users cannot directly use all the capabilities of HTML, such as JavaScript and Cascading Style Sheets. Consistency in look and feel is also achieved: In many wiki implementations, an active hyperlink is exactly as it is shown, unlike in HTML where the invisible hyperlink can have an arbitrary visible anchor text. This goes along with some extra safety for the user: Permitting users to write in unfiltered HTML might allow harmful or annoying code (for example, JavaScript code that prevents the reader from marking part of the text).

MediaWiki syntax	Equivalent HTML	Rendered output
"''Doctor''? No other title? A ''scholar''? And he rates above the civil authority?" "Why, certainly," replied Hardin, amiably. "We're all scholars more or less. After all, we're not so much a world as a scientific foundation &mdash; under the direct control of the Emperor."	<p> "<em>Doctor</em>? No other title? A <em>scholar</em>? And he rates above the civil authority?" </p> <p> "Why, certainly," replied Hardin, amiably. "We're all scholars more or less. After all, we're not so much a world as a scientific foundation &mdash; under the direct control of the Emperor." </p>	"Doctor? No other title? A scholar? And he rates above the civil authority?" "Why, certainly," replied Hardin, amiably. "We're all scholars more or less. After all, we're not so much a world as a scientific foundation — under the direct control of the Emperor."

(Quotation above from Foundation by Isaac Asimov)

Some recent wiki engines use a different method: they allow "WYSIWYG" editing, usually by means of JavaScript or an ActiveX control that translates graphically entered formatting instructions, such as "bold" and "italics", into the corresponding HTML tags. In those implementations, the markup of a newly-edited HTML version of the page is generated and submitted to the server transparently, and the user is shielded from this technical detail. Users who do not have the necessary plugin can generally edit the page, usually by directly editing the raw HTML code. More recently, wiki engines are generating wiki syntax instead of HTML. This way, users who are comfortable editing in wiki syntax can carry on.

Although for years the de facto standard was the syntax of the original WikiWikiWeb, currently the formatting instructions vary depending on the wiki engine. Simple wikis allow only basic text formatting, whereas more complex ones have support for tables, images, formulas, or even interactive elements such as polls and games. At present there is no standard for wiki markup.

Linking and creating pages

Wikis are a hypertext medium, with non-linear navigational structures. Each page typically contains a large number of links to other pages. Hierarchical navigation pages often exist in larger wikis, often a consequence of the original page creation process, but they do not have to be used. Links are created using a specific syntax, the so-called "link pattern".

Originally, most wikis used CamelCase when naming program identifiers, produced by capitalizing words in a phrase and removing the spaces between them (the word "CamelCase" is itself an example). While CamelCase makes linking very easy, it also leads to links which are written in a form that deviates from the standard spelling. CamelCase-based wikis are instantly recognizable because they have many links with names such as "TableOfContents" and "BeginnerQuestions". Note that it is possible for a wiki to render the visible anchor for such links "pretty" by reinserting spaces, and possibly also reverting to lower case. However, this reprocessing of the link to improve the readability of the anchor is 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 letters 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, and sometimes a full-text search. The scalability of the search depends on whether the wiki engine uses a database; indexed database access is necessary for high speed searches on large wikis.

Server-side versus client-side wiki

By far, the most common wiki systems are server-side. In essence, the edit, display and control functions are provided on the server through the wikiengine that renders the content into an HTML-based page for display in a web browser.

A client-side wiki system requires only that the server "serve" wiki files in much the same way that a web server allows HTML files to be retrieved using HTTP. In this type of wiki system, all the execution required to convert the underlying wiki text into an onscreen formatted display page resides in the client browser. Likewise, the editing tools and functionality reside in the browser.

The client-side wiki system parallels HTML in that the page becomes a rendering instruction for the browser to interpret. Client-side wiki systems may be little more than a code plugin to a more traditional web browser.

Web-based versus peer-to-peer

Most wikis are based on a web server. The server can be open to everybody on the Internet, or part of a private LAN, with limited access. There is also a version of wiki that can be shared between peers, with no need for a web server. Such Peer-to-peer wiki system is integrated with a P2P version-control system that takes care of versioning and distribution of pages.

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 numbering recent edits, or a list of all the edits made within a given timeframe. Some wikis can filter the list to remove minor edits and edits made by automatic importing scripts ("bots").

From the change log, other functions are accessible in most wikis: the Revision History showing previous page versions; and the diff feature, highlighting the changes between two revisions. Using the Revision History, an editor can view and restore a previous version of the article. 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 him or her to verify the validity of new editions quickly.

Vandalism

The open philosophy of most wikis—of allowing anyone to edit content—does not ensure that editors are well-meaning. The approach of making damage easy to undo rather than attempting to prevent damage has been characterized as soft security.^[7] Many editors of wiki sites tend to have good intentions, although on larger wiki sites, such as those run by the Wikimedia Foundation, vandalism can go unnoticed for a period of time. Wikis by their very nature are susceptible to intentional disruption, "trolling".

Wiki communities

Many wiki communities are private, particularly within enterprises as collaborative software. They are often used as internal documentation for in-house systems and applications. The democratic, all-encompassing nature of Wikipedia is a significant factor in its growth, while many other wikis are highly specialized.

There also exist WikiNodes which 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: Wikipedia's Tour Bus Stop. Domain names containing "wiki" are growing in popularity to support specific niches.

For those interested in creating their own wiki, there are many publicly available "wiki farms", some of which can also make private, password-protected wikis. PeanutButterWiki, BrainKeeper, Socialtext, Wetpaint, and Wikia are popular examples of such services. For more info, see List of wiki farms.

The English-language Wikipedia is the largest wiki^{[citation needed]}. The other Wikipedias fill many of the remaining upper slots. Other large wikis include the WikiWikiWeb, Memory Alpha, Wikitravel, World66 and Susning.nu, a Swedish-language knowledge base. The largest wikis are listed and updated on Wikimedia's "meta" wiki. Many public wikis are listed at WikiIndex, which is a wiki of wikis.

Wikis and content management systems

Wikis have shared, and encouraged, several features with generalized content management systems (CMS) which are used by enterprises and communities-of-practice. Those looking to compare a CMS with an enterprise wiki should consider these basic features:

1. The name of an article is embedded in the hyperlink.
2. Articles can be created or edited at anytime by anyone (with certain limitations for protected articles).
3. Articles are editable through the web browser.
4. Each article provides one-click access to the history/versioning page, which also supports version differencing ("diff") and retrieving prior versions.
5. Each article provides one-click access to a discussion page particular to that article.
6. The most recent additions/modifications of articles can be monitored actively or passively.

None of these are particular to a wiki, and some have developed independently. Still the concept of a wiki unequivocally refers to this core set of features. Taken together, they fit the generative nature of the Internet^[8], in encouraging each user to help build it. It is yet to be studied whether an enterprise wiki encourages more usage, or leads to more knowledgeable community members, than other content management systems.

See also

Find more information on wiki by searching Wikipedia's sister projects
	Dictionary definitions from Wiktionary
	Textbooks from Wikibooks
	Quotations from Wikiquote
	Source texts from Wikisource
	Images and media from Commons
	News stories from Wikinews
	Learning resources from Wikiversity

• Comparison of wiki farms
• Comparison of wiki software
• Bliki
• List of wikis
• List of wiki software
• Massively distributed collaboration
• Wiki farm
• Semantic wiki
• Social software
• Content management
• Content management system
• Wikipedia
• Wikipedia community

Notes

References

External links

• WikiWikiWeb (the first wiki)
• Wikis at HowStuffWorks.
• "Information Wants to be Liquid" — Wired magazine article
• What makes an 'enterprise' wiki Critical review of wikis in the enterprise
• Science in the Web Age: Joint Efforts on wikis and the scientific community, from Nature magazine
• Operation of a Large Scale, General Purpose Wiki Website Book abstract