For other uses, see Wiki (disambiguation). "WikiNode" redirects here. For the WikiNode of Wikipedia, see Wikipedia:WikiNode. "Flagged revisions" redirects here. For its proposed implementation on Wikipedia, see Wikipedia:Flagged revisions

A wiki (from Hawaiian, meaning "quick") is a content management system (CMS) for websites, designed to facilitate the rapid and collaborative editing of documents in an online database, through an in- browser text interface that hides most of the technical and tedious aspects of web publishing. Wiki documents, called " pages" or " articles," are publicly available as web pages, and are editable— such that when saved they are posted to the server, where they are rendered immediately into web pages.

Like other web server-CMS's, wikis provide a much simpler web interface to more sophisticated website creation functions such as creating URLs, HTML editing, FTP uploading, use of script functions, and database entry. Contribution and modification of content on wikis is made particularly easy (i.e., "quick") via the implementation of two basic concepts:

1. a simplified " wiki markup" syntax ^{[1] [2]} that allows the trivially easy editing of internal (site-specific) hyperlinks and text-formatting code. Wikitext is stored in raw form and translated upon request into web-viewable HTML (or other presentation formats such as PDF).
2. an integrated web server and database management system (DBMS) layout, edited through a web form. Pages in the database are associated with a logical URLs scheme, allowing direct external (offsite) access to particular pages.

Conceptually, wikis are both content-driven and user-agnostic, such that revision control methods such as edit rollbacks ( revision histories, edit comparisons) and community correction are preferred over identity-based access controls such as verification of user accounts and access credentials. However different variations of this theme exist in most real-world implementations, and each considers a balance between the value of access versus the value of data. For example, the collaborative encyclopedia Wikipedia is one of the best-known wikis, ^[2] and its success is largely due to its open access and open source philosophy. Wikis used for other knowledge management purposes may have a very different philosophy, and technical implementations may differ accordingly —ranging from limited-access websites to corporate intranet and VPN systems to highly secretive systems using secretive protocols (see Intellipedia).

Ward Cunningham, the developer of the first wiki software, WikiWikiWeb, originally described it as "the simplest online database that could possibly work." ^[3] His original wiki ran on a flat file database system. Later variations and implementations of the concept usually make use of DBMSs. Unlike other proprietary variants, Cunningham's implementation was in the public domain, using in a readable scripted language in an open source language ( PHP), and was an example of the innovation and impact of the open source philosophy as applied to the Internet.

Due to their power and ease of use, wikis are often used for collaborative and community websites, and are typically associated with the open source model of development. While wikis (strictly defined) have their limitations, such that other CMS models may be better suited for certain uses, the widespread and popular usage of wikis for creating and managing documents represents an innovation and leap forward in the development of the World Wide Web (cf. Web 2.0).

For his new technology, Cunningham chose the word "wiki" ( /wiːkiː/, "wiki wiki" is a reduplication), the Hawaiian word for "fast," ^[4] precisely for the reason that content creation on his platform would be far quicker than HTML editing. "Wiki" can be expanded as "What I Know Is," but this is a backronym. ^[5]