The Wiki application was first used 1995, on a page called the WikiWikiWeb set up by a company called Cunningham & Cunningham in Portland. The application allows for any web user to add and edit content a website - often in a completely unrestricted way. This has created a fundamental change in the way information is collected online, allows for co-authoring and the collective creation of webpages.
Wiki is most useful when set up as an information source, and is commonly employed in creating support pages for various topics. Its collaborative nature allows for many different ideas to be contributed, which allows for a knowledge base to be expanded rapidly. Think of thousands of people throwing in their two-cents on a problem and you'll see how a wiki page can be a valuable tool.
A wiki web page works by using 'wikitext' which acts as a middleman between the user and the HTML code the server requires. If the user desires to edit or add to a wiki web pages, the may view the source of the page in wikitext, which shows in coding of the web page in something very close to plain language. The problem for the average user with HTML code is that is has many programming commands that make it difficult to decipher if you want to edit text. Wikitext acts as a mediator with its simple commands. When the user is finished editing the wikitext to his or her satisfaction the text is uploaded to the server where wiki software converts it to the more complicated HTML code required for web pages.
One of the most interesting using of the wiki application is the wikipedia. The wikipedia started in 2001 and has turned into a giant, collaborative encyclopedia. Written entirely by volunteers, the wikipedia functions very much like any other online encyclopedia, with the important exception that anyone can add entries, or expand existing entries. So if you visit a page and see something that you know to be incorrect or unclear, you may contribute an edited version of the entry. And if you are knowledgeable on a subject that has no entry in the wikipedia, you may write your own.
Whereas most encyclopedias are written by a relatively small group of academic writers assigned to various topics, the wikipedia is written by many thousands of individuals. The nature of the wiki software makes it easy for someone who may be knowledge about a particular obscure topic to contribute, and as more people contribute, the scope of the wikipedia broadens.
Currently, the wikipedia is maintained by a non-profit foundation relying mainly on donations. Some users have expressed in interest in a wikipedia cd, which would allow the encyclopedia to be installed locally on a machine, much the same way as other encyclopedias have cd versions. There are currently no plans for a wikipedia cd, although such a project would no doubt create revenue for the foundation. The fact that a wikipedia cd is seen as not necessary speaks to how effective the wikipedia project has been, and its continued success in the future is likely.