- we have a web service with its own authentication system (not any of the widespread CMSs - the custom one)
- we want it to have a forum
- however, we want the forum to use the same user logins and other data, e.g. who is admin and who's not, how many 'stars' you've got and so on
- we don't want to build forum solution ourselves - instead we want to use some well-known engines like phpBB, vBulletin or similar. Hosted solutions are also an option.
we failed to find any "plug-and-play" solution for this, supposingly widespread, problem. So what's the right way to approach it?