Wiki (from the Hawaiian word wikiwiki for "quick") is a web site metaphor invented by Ward Cunningham in 1994.

Wiki web sites are wide open to editing by anybody. Users do not have to log in before being able to edit, and are allowed to change all pages. A history of all previous versions of a page is kept, so that unintended, undesirable or malicious changes can be easily undone. A central page, usually called RecentChanges, logs all edits and active participants on a Wiki typically monitor this page constantly, leading to remarkably few problems with trolls and vandals.

Wikis use a simplified markup language intended to achieve a most painless editing experience. For instance:

  • All page names are MixedCase words, and any such word automatically turns into a link. External links can be constructed using the format [ Everything2].
  • Emphasizing is done with two single quotes: this is ''important.''
  • A list is constructed with
    * first item
    * second item
The Wiki software (several Wiki cgi scripts written in C, perl and php exist by now) converts this markup into HTML for presentation.

Cunningham's original Wiki is organized as a large collection of programming ideas, patterns and related discourse. It also contains introductions to the Wiki concept and links to many Wikis and to the available Wiki software; it can be found at

The Wikipedia project uses the Wiki metaphor to create a copyleft encyclopedia. It is the largest Wiki in existence.

This writeup is in the public domain.

The concept of a Wiki was invented by Ward Cunningham, taking its name from the Hawaiian word wikiwiki, meaning quick. It is worth noting that there is a Hawaiian bus company called Wikiwiki. It may be coincidence or a clever pun that Wiki also stands for "What I know is".

What a Wiki is

In principle, a Wiki is a website or a content management system where the content is written by anyone, i.e. the system is open access. Also, there is no requirement to learn HTML, as the Wiki software provides its own markup language. This includes a method of linking entries together.

What Wikis are used for

A Wiki can be used anywhere that a group of people want to share a common pool information, especially where the information is collectively owned and there are no issues with authorship, credit or copyright.

Wikis on the Internet allow for a very large audience of contributors. An example is the Wikipedia, whose aims are similar to E2.

A Wiki can be used in a university department, as a bulletin board for all information and administrative matters.

I have also seen a Wiki being used in a geek household, to keep track of all the bills, as well as a creative braindump receptacle.

Wikis work very well on corporate intranets, promoting free thinking and knowledge sharing amongst staff. Populating a wiki with a braindump has been considered a number one task before leaving the job, at one place I have worked.1

Is Everything2 a Wiki?

Although E2 has much in common with Wikis, there are fundamental differences.
  • Firstly, in order to contribute to E2, you must register a username with E2 supplying a valid email address. Although this is an option with Wikis, most are completely open access.
  • E2 also has a hierarchy of users with differing capabilities and privileges, based on XP and/or number of writeups. On a wiki, excepting those with administrator access to the server, all users are (created) equal.
  • E2 has a defined authorship for each writeup. Apart from showing the last person who changed an entry, Wikis do not show authorship, nor do they prevent others from editing any existing entry. This means that in a Wiki, there is no need for special "editor rights" as anyone can edit.
  • Finally, the content of E2 has a defined legal copyright status, and policy on the site is clearly stated. Wikis tend to be open and anarchistic. If there is any policy, the sites are usually copyleft.

See also the node wikipedia.

There is no reason in theory why someone couldn't use the Everything Engine to run a Wiki, by turning off all the user access controls and making everyone an editor or god.

Content recovery

You may be wondering how Internet Wiki sites deal with abuse, including trolling, flame and graffiti. The solution adopted by most wikis is quite simple, the Wiki software contains a revision control system. Each entry has a complete change history, Everyone can go back through time and view the previous versions of any entry. For the abuse, it then becomes a simple matter for someone who notices to change it back.

The legal position on this is quite moot. Can you sue a Wiki site for libel? Who becomes culpable?

Wiki markup language (usemod)

Paragraphs happen automatically by use of a single blank line.

Headings are achieved by enclosing a line in a number of ==

= Head 1 =
== Head 2 ==
=== Head 3 ===
==== Head 4 ====
===== Head 5 =====
====== Head 6 ======
Similarly, bullet point lists can be nested using lines beginning '*':
* Items:
** foo
** bar
** baz
* Extras:
** grault
** quux
Numbered lists work in the same way, but with '#' instead of '*'.

Text can be highlighted by using different numbers of single quotes: (note that in the second or third cases, the quotes are not actually displayed)

'ordinary quoted'

Wiki links

To provide a link on the site, the original idea was to use camelCase. The software detects words containing an upper case letter prefixed by a lower case letter, and turns fooBar into a hyperlink to page fooBar.

Later, placing in a pair of square brackets enabled linking to a phrase, such as [[The moon is made of cheese]]. Pipe linking was also introduced.

Wikis also have a means of linking offsite. This is done by placing the URL in a single set of square brackets, e.g. [], and pipe linking is also available here.

Wiki sites
Home of the original Portland Pattern Repository set up by Ward Cunningham.
The Wikipedia copyleft encyclopaedia
openwiki is Laurens Pit's open source Wiki
see twiki
This one is pretty much shrink wrapped, and I have installed a usemod site from scratch in about half an hour including download time.
The Moinmoin Wiki written in Python.
The OpenGuides project for community gazetteers


1 I left this company as a result of a takeover, and signs that things were beginning to change. Allowing and encouraging an intranet Wiki is a sign of a good company to work for. Too many of the big corporates are too political, pig ignorant or paranoid to allow a Wiki on an intranet site.

The differenences between E2 and a Wiki:

  • Wikis are content or community centered, E2 is all-pupose and general.
  • Wikis usually give unfettered access to the entire document without the by-user grouping that E2 imposes.
  • Wikis have a tree structure with a simple starting page and nodes branching off from there, with nodes being uniquely identified by name. E2 has no central page or tree heirarchy.

Contrary to what ponder says:

  • Registering is an option in almost all modern wikis, simply due to the idiocy of the average internet user who might stumble upon a wiki.
  • Any fully-featured wiki will contain the ability to diff a page and see who made what modifications and what the document looked like revisions ago.

Other important differences between E2 and Wiki:

  • The dynamic inclusion of soft links due to the browsing behaviour of users is currently only a feature of E2 and quite often provides interesting new directions to find related topics in.
  • Wikis allow direct linking to URLs of other websites, while linking in E2 is limited to hard and soft links. (see E2 FAQ: Links for more)
  • The editing features on Wikis use a proprietory syntax to format pages, while E2 has proprietory syntax most of the standard HTML Tags are allowed. (see E2 HTML tags : Quick Start for more)
  • Wikipedia has a directly linked discussion tab to discuss or note changes that need to be made to content, this is handled differently in E2 since each user that adds information adds a separate writeup for further information.
  • A related is that E2 nodes can contain conflicting or complementory information since there can be several writeups to a node; while in Wiki an entry is generally a more coherent or a single viewpoint.

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