Seeking a web 2.0 app for Quest Tracking

I’m looking for a particular kind of web 2.0 app, but can’t track down something which does what I want.  It’s mostly related to MMORPG’s but I can imagine non-gaming uses for it.  If you have a bunch of people all at different stages of some kind of activity which itself has multiple stages and sub-stages, it can often be hard working out who’s at what point.

I’d love an app in which you could create multiple personalities (characters) and set up these tasks (quests) with all their sub-stages (other quests) and then let people track their progress.  You would be able to inquire as to the progress of a specific character, or a collection of characters.  Tasks could have pre-requisites or tasks which must be completed first, etc.

I can (and have in the past) knocked together something simple which does something similar, but I get bored easily doing web development and a lot of it is very repetative, also I’ve never really gotten to grips with the 2.0 side of web 2.0.  Do you know of any app out there that does this?  Maybe it’s a project management tool that allows multiple people to work on the same tasks at different rates, or maybe it’s a specific gaming tool?

Let me know if I’m missing the obvious.