I'm not absolutely certain whether this should be here or on Web Applications, but here goes.
I need wiki software, preferably something that runs on PHP but this is not a hard requirement, which supports namespaces. That is, I need to be able to give users an arbitrary number of wiki spaces that do not overlap or interact with each other. FOSS is preferred as well.
I've been unable to find something like this so far, so I may have to roll my own solution. Does anyone know of such an application?