So basically I'm trying to set up a system where there are 3 kinds of users. I would be the only back end user, then there would be organizers and participants. I set up the organizers (who are very consistent - very little upkeep) and they set up the participants who change every so often. Then the participants are able to log on only after the organizer has allowed it. They can make changes to their profile and stuff like that and only see their own info.

I don't want to have to code any of this; I just don't have the time. Does anyone know which CMS would be best for something like this?