ganfydd is a qualified medical reference wiki established in the UK. It uses the Mediawiki software and has a variant Creative Commons content licence.
Wikipedia is a very successful general encyclopedia based on the principle of general edit access. ganfyd aims to offer material which has been edited only by qualified people, but otherwise will operate in a similar fashion.
Several of the early editors are Wikipedia editors and contributors, and the difference between the projects intended contents is that between the encyclopedia, and the shelf of medical textbooks.
The project is in a very early stage, and styles are evolving.
The excellent Open Source MediaWiki software is a considerable element in easily setting up such a system, and is in use in a growing number of UK and Australian Medical Practices already as a general reference system.