What is a Wiki?
A wiki (pronounced "wicky" or "weeky" or "viki") is a website (or other hypertext document collection) that allows any user to add content, but also allows that content to be edited by any other user while keeping track of the different versions.
In short, a Wiki is one of the most powerful tools for web-based collaborative editing and a prominent example of emerging social software.
A WikiEngine is the software used to create and run such websites. For instance, this wiki runs on the WikkaWiki engine.
More information on Wikis is available on: Wikipedia
