Wikitravel is a project to create an open content, complete, up-to-date, and reliable world-wide travel guide. Although it uses a Wiki model to create the guide and deliver it on the World Wide Web, the project is also aimed towards production of print-quality guides.
The project uses MediaWiki, which is also used by the Wikipedia. It is built in collaboration by Wikitravellers from around the globe, and uses the Creative Commons Attribution Share Alike license  to keep the guide free.
See also: CapitanCook