CitiWiki is a fork of the original WakkaWiki. The objective of CitiWiki is to create a platform for research into Wiki-related technologies. CitiWiki itself is being used to implement a wiki system for the Department of Computer Science that acts as a knowledge management system (KMS) to collect and organize knowledge related to Computer Science in general, with contributions from both CS students and staff. This CS knowledge-base is here.
The CitiWiki fork was created since we envision substantial code changes will be made to the original WakkaWiki for our research and experimentation. You could take a look at WikiDev? to find out more on some of our development details. We plan to make CitiWiki source code available to the general public.