The original intent of wiki is to allow anyone to freely create and edit contents on the web. However, vandalism prompted many organizations to build in a validation mechanism. So wiki has evolved to be a controlled collaboration. That makes sense. You don't want your wiki to present misleading info or someone else to delete your contents. "Library Success: A Best Practices Wiki" is a good example.
We could create a wiki for UMD Library Technical Services, say, for a manual of operational procedures. Each staff can create and edit the contents in their own resposible areas.