Wiki is a Hawaiian word meaning "fast" or "quick". Wiki applications is is collaborative software that runs a wiki. A wiki is a web site which users can add, modify, or delete its content via a web browser using a simplified markup language or a rich-text editor. Wiki allows users to create and collaboratively edit web pages via a web browser. Examples of wiki use include community websites, corporate intranets, knowledge management systems, and notetaking.
Main features of Wiki:
- Wiki users can edit any page or to create new pages within the wiki web site, using only a plain 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.
- 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.
Wiki enables users 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. Wiki is essentially a database for creating, browsing, and searching through information. A wiki allows for non-linear, evolving, complex and networked text, argument and interaction.
A defining characteristic of wiki technology is the ease with which pages can be created and updated. 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.
Within the text of most pages there are usually a large number of hypertext links to other pages. Wikis generally provide one or more ways to categorize or tag pages to support the maintenance of such index pages. Users can create any number of index or table-of-contents pages, with hierarchical categorization or whatever form of organization they like. Most wikis have a backlink feature, which displays all pages that link to a given page. 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.
Wikis are generally designed with the philosophy of making it easy to correct mistakes, rather than making it difficult to make them. Thus, while wikis are very open, they provide a means to verify the validity of recent additions to the body of pages. The most prominent, on almost every wiki, is the Recent Changes page which is a specific list numbering recent edits, or a list of edits made within a given time frame.
From the change log, other functions are accessible in most wikis: the revision history shows previous page versions and the diff feature highlights the changes between two revisions. Using the revision history, an editor can view and restore a previous version of the article. The diff feature can be used to decide whether or not this is necessary. A regular wiki user can view the diff of an edit listed on the "Recent Changes" page and, if it is an unacceptable edit, consult the history, restoring a previous revision.
In case unacceptable edits are missed on the "recent changes" page, some wiki engines provide additional content control. It can be monitored to ensure that a page, or a set of pages, keeps its quality. A person willing to maintain pages will be warned of modifications to the pages, allowing him or her to verify the validity of new editions quickly.
Some wikis also implement "patrolled revisions," in which editors with the requisite credentials can mark some edits as not vandalism. A "flagged revisions" system can prevent edits from going live until they have been reviewed.
Most wikis offer at least a title search, and sometimes a full-text search. The scalability of the search depends on whether the wiki engine uses a database.
There are essentially three types of usage for wiki: public wikis with a potentially large community of readers and editors, enterprise wikis for data management by corporations and other organizations, and personal wikis, meant to be used by a single person to manage notes, and usually run on a desktop. Some wiki applications is specifically geared for one of the usage types, while other software can be used for all three, but contains functionality, either in its core or through plugins, that help with one or more of the usage types.
Public wikis are wikis that can be read by anyone and they usually (though not always) can be edited by anyone as well with sometimes required registration. Among public wikis, MediaWiki is the major application. It is used for the most popular public wiki, Wikipedia, as well as for the most popular wiki farm, Wikia, and it is the most popular application in use on other public wikis as well. Other wiki engines used regularly for public wikis include MoinMoin and PmWiki, along with many others.
Enterprise wiki application is used in a corporate (or organizational) context, especially to enhance internal knowledge sharing, with a greater emphasis on features like access control, integration with other software, and document management.
Most wiki applications are enterprise solutions including Confluence, Socialtext, Jive Engage, SamePage, and Traction TeamPage. In addition, some open source wiki applications also describe themselves as enterprise solutions including Foswiki which calls itself "free and open source enterprise collaboration platform", and TWiki, which calls itself "Open Source Enterprise Wiki". Some open source wiki applications, though they do not specifically call themselves as enterprise solutions, have marketing materials geared for enterprise users, like Tiki Wiki CMS Groupware and MediaWiki. Many other wiki applications have also been used within enterprises.
Within organizations, wikis may either add to or replace centrally managed content management systems. Their decentralized nature allows them to disseminate needed information across an organization more rapidly and more cheaply than a centrally controlled knowledge repository. Wikis can be used for document management, project management, customer relationship management, enterprise resource planning, and many other kinds of data management.
Features of wikis specifically helpful to a corporation include:
- Allow to connect information using quick and easy to create pages containing links to other corporate information systems, like people directories, CMS and thus build up knowledge bases.
- Avoiding e-mail overload. Wikis allow all relevant information to be shared by people working on a given project. Only the wiki users interested in a given project need look at its associated wiki pages, in contrast to high-traffic mailing lists which may burden subscribers with many messages, regardless of relevance to particular subscribers. It is also very useful for the project manager to have all the communication stored in one place, which allows them to link the responsibility for every action taken to a particular team member.
- Organizing information. Wikis allow users to structure new and existing information. As with content, the structure of data is sometimes also editable by users.
- Building consensus. Wikis allow the structured expression of views disagreed upon by authors on a same page. This feature is very useful when writing documentation, preparing presentations and so on.
- Access rights, roles. Users can be forbidden from viewing and/or editing given pages, depending on their department or role within the organization.
- Knowledge management with comprehensive searches. This includes document and project management, as well as using a wiki as a knowledge repository useful during times of employee turnover, retirement and so on.
Application that is specifically designed for running personal wikis includes NotePub, Pimki and Tomboy. Other, more general, wiki applications have components geared for individual users, including MoinMoin, which offers a Desktop Edition.
Wiki applications can include features that come with traditional content management systems, such as calendars, tasks lists, blogs, and discussion forums. All of these can either be stored via versioned wiki pages, or simply be a separate piece of functionality. Applications that support blogs with wiki style editing and versioning is sometimes known as "bliki" software. Tiki Wiki CMS Groupware is an example of wiki software that is designed to support such features at its core. Many of the enterprise wiki applications, such as TWiki, Confluence and SharePoint, also support such features, as do open source applications like MediaWiki and XWiki, via plugins.
Wiki software can let users store data via the wiki, in a way that can be exported via the Semantic Web, or queried internally within the wiki. A wiki that allows such annotation is known as a semantic wiki. The current best-known semantic wiki software is Semantic MediaWiki, a plugin to MediaWiki.