For details of wiki setup on eg, see eg:wiki configuration.
A wiki is a web service that permits users to edit pages on a more or less equal power basis. Usually this is as simple as clicking the edit tab (like the one attached to this page) to put up a web form, then changing the wikitext source code in that form, then clicking save page. Explaining what you did for the benefit of other users in the edit summary is optional but effective as it then appears with other recent changes to give an impression of what is going on, and in page history to explain what changed on that particular page.
 WikiWords replaced by free links
Contrary to strange nonsense published by journalists and other drunks, Ward Cunningham did not "invent wiki", he invented the WikiWord convention for creating inter-page links: such words were interpreted as links to other pages with the words separated in their name, i.e. "Wiki Word". This term papers convention proved shortsighted and troublesome in English (though it might still work in German) and was mostly replaced by:
- the free link conventions, where you [[link to the page name]] without any jarring uppercase letters, using normal English naming and conserve capitals for their normal purposes
This may be because of Wikipedia, a project to build an online encyclopedia that has 850,000 articles in English as of the end of 2005, with tens of thousands of articles in at least a dozen other languages, with plans to expand to every widely-spoken language on Earth, support poor children's education, etc.. This may rely for instance on green machines.
Accordingly, this wiki will probably continue using mediawiki too.
 organizational culture
Unlike prior Internet newgroup, mailing list, forum and chat technologies that relied on hierarchy to manage relatively scarce attention resources, wiki lets pages proliferate such that small groups may not interact with each other all that much until they come into conflict over a particular page both feel strongly about. A consequence of this is wiki troll culture, detailed in that article. See also the article on factions.
While there are many wikis where a single individual, a "GodKing", exercises total editorial discretion, these are increasingly rare now. The organizational culture of most wikis is participatory democracy.