wiki


 * A Wiki


 * A wiki is software that allows users to create, edit, and link web pages easily. Wikis are often used to create collaborative websites and to power community websites. They are being installed by businesses to provide affordable and effective Intranets and for Knowledge Management. Ward Cunningham, developer of the first wiki, WikiWikiWeb, originally described it as "the simplest online database that could possibly work". One of the best known wikis is Wikipedia.

Wiki Wiki (/wiːkiː wiːkiː/) is a reduplication of wiki, a Hawaiian word for "fast." In English, "wiki" is an abbreviation of it. WikiWikiWeb was the first site to be called a wiki. Ward Cunningham started developing WikiWikiWeb in 1994, and installed it on the 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 "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. Cunningham was in part inspired by Apple's HyperCard. Apple had designed a system allowing users to create virtual "card stacks" supporting links among the various cards. Cunningham developed Vannevar Bush's ideas by allowing users to "comment on and change one another's text".[2][5] In the early 2000s, wikis were increasingly adopted in 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.**

Characteristics**

A wiki enables documents to be written 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 collection of pages, which are usually well interconnected by hyperlinks, is "the wiki". A wiki is essentially a database for creating, browsing, and searching through 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 alteration by the general public without requiring them to register user accounts. Sometimes logging in for a session is recommended, to create a "wiki-signature" cookie for signing edits automatically. Many edits, however, can be made in real-time and appear almost instantly online. This can facilitate abuse of the system. Private wiki servers require user authentication to edit pages, and sometimes even to read them.


 * Editing wiki pages**

Ordinarily, the structure and formatting of wiki pages are specified with a simplified markup language, sometimes known as "wikitext". For example, starting a line of text with an asterisk ("*") is often used to enter it in a bulleted list. The style and syntax of wikitexts can vary greatly among wiki implementations, some of which also allow HTML tags. The reason for taking this approach is that HTML, with its many cryptic tags, is not very legible, making it hard to edit. Wikis therefore favour plain text editing, with fewer and simpler conventions than HTML, for indicating style and structure.

Although limiting access to HTML and Cascading Style Sheets (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 disabled prevents a user from implementing code, which may limit access for other users. Increasingly, wikis are making "WYSIWYG" ("What You See Is What You Get") editing available to users, 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 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, and the user is shielded from this technical detail. However, WYSIWYG controls do not always provide all of the features available in wikitext. Many implementations (for example MediaWiki) allow users to supply an "edit summary" when they edit a page. This is a short piece of text (usually one line) summarizing the changes. It is not inserted into the article, 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 committing changes to a revision control system. Most 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 or the page has been vandalised.


 * Navigation**

Within the text of most pages there are usually a large number of hypertext links to other pages. This form of non-linear navigation is more "native" to wiki than structured/formalized navigation schemes. That said, 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 create and delete pages in an ad hoc manner. Wikis generally provide one or more ways to categorize or tag pages, to support the maintenance of such index pages. Most wikis have a backlink feature, an easy way to see what pages link to the page you're currently on. It is typical 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.


 * Linking and creating pages**

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

Example: Wikipedia online encyclopedia