From SAGESWiki

Wikis are a form of software for the web that allow simplified access to editing content. They:

• are based on pages associated with terms -- any wiki entry is a single page (such as this page) linked to a term (for this page, that term is "About wikis"), although entries can have alternative names and be subdivided
• allow any users with the proper rights to edit entries through their browser, usually with one-click access
• maintain versions -- that is, users can see previous edits of an entry and compare any two versions to one another to see what changed
• use markup language -- there is a method of formatting your entries (to make words bold or italic, to add a link, to insert an image, etcetera) that does not require users to know HTML
• use a database as a back-end -- the information is not stored in HTML files, but pulled from a database when needed

A two-paragraph history of wikis

Wikis were invented by a programmer named Ward Cunningham in 1995 for a site he ran, the "Portland Pattern Repository" (currently hosted at c2.com). He wanted an easy way for people to contribute to discussions about design methodologies in programming. Cunningham wanted to call his software "QuickWeb", but discovered that the name was already in use by several other projects. "Wiki" is the Hawaiian word for "quick"; the shuttles to the Honolulu airport are called "Wiki Wiki" (which means "very quick" thanks to the wonders of reduplication. Cunningham thus called his projected "WikiWikiWeb". The project became hugely popular, and because most of Cunningham's original user base was programmers, many decided to recreate and improve on his wiki software, and the use of wikis to create online knowledge bases (for uses such as documentation, help desk software, and reference works) began to spread.

One of the people who discovered wikis was an independently wealthy options trader, James "Jimbo" Wales, who hired a programmer named Larry Sanger to develop software for a wiki-based encyclopedia. The project, the Wikipedia has grown into a reference work over five times the size of the Encyclopedia Britannica. The software Sanger and later Wikipedia programmers developed was eventually released as a free, open-source software package called MediaWiki, which this site uses.