In their 2001 book
The Wiki Way: Quick Collaboration on the Web,
Ward Cunningham and co-author
Bo Leuf described the essence of the wiki concept: • "A wiki invites all users—not just experts—to edit any
page or to create new pages within the wiki website, 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 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."
Editing Source editing Some wikis present users with an edit button or link on the page being viewed. This will open an
interface for writing, formatting, and structuring page content. The interface may be a
source editor, which is text-based and employs a
lightweight markup language (known as
wikitext,
wiki markup, or
wikicode), or a
visual editor. For example, in a source editor, starting lines of text with
asterisks could create a
bulleted list. The
syntax and features of wiki markup languages for denoting style and structure can vary greatly among
implementations. Some allow the use of and , while others disallow them to foster uniformity in appearance.
Example of syntax A short section of the 1865 novel ''
Alice's Adventures in Wonderland'' rendered in wiki markup: does not require a closing tag. -->
Visual editing While wiki engines have traditionally offered source editing to users, in recent years some implementations have added a
rich text editing mode. This is usually implemented, using
JavaScript, as an interface which translates formatting instructions chosen from a
toolbar into the corresponding wiki markup or HTML. This is generated and submitted to the server
transparently, shielding users from the technical detail of markup editing and making it easier for them to change the content of pages. An example of such an interface is the
VisualEditor in
MediaWiki, the wiki engine used by Wikipedia.
WYSIWYG editors may not provide all the features available in wiki markup, and some users prefer not to use them, so a source editor will often be available simultaneously.
Version history Some wiki implementations keep a record of changes made to wiki pages, and may store every version of the page permanently. This allows authors to revert a page to an older version to rectify a mistake, or counteract a malicious or inappropriate edit to its content. These stores are typically presented for each page in a list, called a "log" or "edit history", available from the page via a link in the interface. The list displays
metadata for each revision to the page, such as the time and date of when it was stored, and the name of the person who created it, alongside a link to view that specific revision. A
diff (short for "difference") feature may be available, which highlights the changes between any two revisions.
Edit summaries The edit history view in many wiki implementations will include
edit summaries written by users when submitting changes to a page. Similar to the function of a
log message in a
revision control system, an edit summary is a short piece of text which summarizes and perhaps explains the change, for example "Corrected grammar" or "Fixed table formatting to not extend past page width". It is not inserted into the article's main text.
Navigation Traditionally, wikis offer free navigation between their pages via
hypertext links in page text, rather than requiring users to follow a formal or structured navigation scheme. Users may also create
indexes or
table of contents pages, hierarchical categorization via a
taxonomy, or other forms of
ad hoc content organization. Wiki implementations can provide one or more ways to categorize or
tag pages to support the maintenance of such index pages, such as a
backlink feature which displays all pages that link to a given page. Adding categories or tags to a page makes it easier for other users to find it. Most wikis allow the titles of pages to be searched amongst, and some offer
full text search of all stored content.
Navigation between wikis Some wiki communities have established navigational networks between each other using a system called
WikiNodes. A WikiNode is a page on a wiki which describes and links to other, related wikis. Some wikis operate a structure of neighbors and delegates, where a neighbor wiki is one which discusses similar content or is otherwise of interest, and a delegate wiki is one which has agreed to have certain content delegated to it. WikiNode networks act as
webrings which may be navigated from one node to another to find a wiki which addresses a specific subject.
Linking to and naming pages The syntax used to create internal hyperlinks varies between wiki implementations. Beginning with
WikiWikiWeb in 1995, most wikis used
camel case to name pages, which is when words in a phrase are
capitalized and the spaces between them removed. In this system, the phrase "camel case" would be rendered as "CamelCase". In early wiki engines, when a page was displayed, any instance of a camel case phrase would be transformed into a link to another page named with the same phrase. While this system made it easy to link to pages, it had the downside of requiring pages to be named in a form deviating from standard spelling, and titles of a single word required abnormally capitalizing one of the letters (e.g. "WiKi" instead of "Wiki"). Some wiki implementations attempt to improve the display of camel case page titles and links by reinserting spaces and possibly also reverting to lower case, but this simplistic method is not able to correctly present titles of mixed capitalization. For example, "
Kingdom of France" as a page title would be written as "KingdomOfFrance", and displayed as "Kingdom Of France". To avoid this problem, the syntax of wiki markup gained free links (called
wikilinks), wherein a term in natural language could be wrapped in special characters to turn it into a link without modifying it. The concept was given the name in its first implementation, in
UseModWiki in February 2001. In that implementation, link terms were wrapped in a double set of square brackets, for example
Kingdom of France. This syntax was adopted by a number of later wiki engines. It is typically possible for users of a wiki to create links to pages that do not yet exist, as a way to invite the creation of those pages. Such links are usually differentiated visually in some fashion, such as being colored red instead of the default blue, which was the case in the original WikiWikiWeb, or by appearing as a question mark next to the linked words. == History ==