A Wiki is esentially a content management system plus.
They can be used to manage web pages (articles, etc.) as well as other documents, and all information in a wiki can be searched and categorized.
They are also a form of groupware, used to enhance communication and collaboration:
- Wiki pages can be changed by anyone; people can work together to create web documents.
- They allow collaborative content work and production, simultaneously.
In other words, a wiki provides two main services in one package: a tool for knowledge creation / collaboration, and a tool for sharing explicit knowledge / managing content.
It strikes me that a perfect application of a Wiki would have been the aula virtual glossary revision that we did at the end of 2007. Instead of offering feedback and having a central agent to make the changes, if it had been a wiki, updates could have been on the spot and dynamic.
An interesting site showing just how a Wiki can be used in terms of KM.
Here is an interesting blog, detailing how wiki's work as KM tools:
Here is a link to a site which contains a Master's thesis on Wikis as tools of Knowledge Management.