If this is a new site which is going to build new features on top of WackoWiki, I would be happy to help (a little).
In 2004 I selected WackoWiki for a couple of sites I wanted to build.
I chose WackoWiki because, compared with other wikis, it has a fairly simple code structure and has the following key features:
- user groups,
- page clusters,
- a page watch facility
I have been thinking about migrating to another platform because development of WackoWiki stagnated.
Features I would like to see added to WackoWiki include:
- a calendar component
- a GUI interface to define user groups (editing config.php by hand is not the best solution)
- a simple way to tailor the navigation bar for all users (while still allowing users to add their own favorites)