Two Forums, Shared Userbase
 

I'm pretty sure this has been asked here before, but I can't seem to find it at all.

What I need is basically to be able to run two seperate forums, and seperate sites entirely, but be able to share the same userbase. That way when one person registers on one forum, he'll also be able to user the second forum without have to re-register, and vice versa.

I already have two owned licenses, so that's not a problem.

Is this even possible? And how? (Note, this needs to be done using 3.5.x, whatever the latest version is)

Well, the way I see it is you'd run both forums off one database...different prefixes. Then edit both of the registration forms to insert a record into both of the user tables, then for the password change, change for both, and so on for all the features you want shared. It shouldn't be too hard, just replicating a query.

When someone registers, what tables are exactly affected though? Just the user table?

Also, the userfields and usertextfields. I'm not overall too sure. You could always take a look in the code.

The most easy way and most upgrade proof, would be to create a new table in each database. When a user registers on Site A, also write a record to that table in the site B database. Now create a scheduled task, that will read that table, and use the datamanager to insert a new user..etc.

It could also be done directly by setting up a second database connection and use that to let the datamanager insert into the other database also, but that could give problems if both forums are not on the same vBulletin version.