Wikis allow people to collaborate on text based documents, share media and documents and comment on each other's work. Once saved a new version is created, so you can always retrieve work if it is modified or deleted. You can also use the revision history to see who has contributed what.
The UCL Wiki allows you to add what are known as macros to your page to show various information dynamically:
Error rendering macro 'gadget' : The gadget at rest/gadgets/1.0/g/com.atlassian.streams.confluence:activitystream-gadget/gadgets/conf-activitystream-gadget.xml was not added to this Confluence instance yet.
