Ward Cunningham and co-author Bo Leuf, in their book The Wiki Way: Quick Collaboration on the Web, described the essence of the Wiki concept as follows:[citation needed]
A wiki invites all users to edit any page or to create new pages within the wiki Web site, using only a plain-vanilla Web browser without any extra add-ons.
Wiki promotes meaningful topic associations between different pages by making page link creation almost intuitively easy and showing whether an intended target page exists or not.
A wiki is not a carefully crafted site for casual visitors. Instead, it seeks to involve the visitor in an ongoing process of creation and collaboration that constantly changes the Web site landscape.
A wiki enables communities to write documents collaboratively, using a simple markup language and a web browser. 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 hyperlinks, is "the wiki". A wiki is essentially a database for creating, browsing, and searching through information. A wiki allows non-linear, evolving, complex and networked text, argument and interaction.[6]
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 registration of user accounts. Many edits 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.
Maged N. Kamel Boulos, Cito Maramba and Steve Wheeler write that the open wikis produce a process of Social Darwinism. "'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. Whilst such openness may invite 'vandalism' and the posting of untrue information, this same openness also makes it possible to rapidly correct or restore a 'quality' wiki page."[7]
Editing wiki pages
Some wikis have an "edit" button or link directly on the page being viewed, if the user has permission to edit the page. This leads to an editing page which allows participants to structure and format wiki pages with a simplified markup language, sometimes known as wikitext (for example, starting a line of text with an asterisk often sets up a bulleted list). The style and syntax of wikitexts can vary greatly among wiki implementations,[example needed] some of which also allow HTML tags. Wikis 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 that may limit other users' access.
MediaWiki syntax
Equivalent HTML
Rendered output
"Take some more [[tea]]," the March Hare said to Alice, very earnestly.

"I've had '''nothing''' yet," Alice replied in an offended tone, "so I can't take more."

"You mean you can't take ''less''?" said the Hatter. "It's very easy to take ''more'' than nothing."
"Take some more tea," the March Hare said to Alice, very earnestly.
"I've had nothing yet," Alice replied in an offended tone, "so I can't take more."

"You mean you can't take less?" said the Hatter. "It's very easy to take more than nothing."
"Take some more tea," the March Hare said to Alice, very earnestly.
"I've had nothing yet," Alice replied in an offended tone, "so I can't take more."
"You mean you can't take less?" said the Hatter. "It's very easy to take more than nothing."
Wikis can make WYSIWYG editing available to