Multiple forums on one server

I know this has been discussed before, but I just can't find any reference to it. I need to run multiple copies of v9.05 on the same server with different SQL databases. The databases are all unique, as-are the domains and forums. I'm using IIS6 with virtual hosts. I recall that there's an identifier in one of the files that needs to be modified so that the application pools don't get mixed-up on the server, but I don't remember where that is.

Even if sites share the same application pool they won't share the same application variables, unless you have set the sites up with the same application name in the IIS snapin.

If you do place multiple forums on the same web site, then you would need to edit the file includes/setup_options_inc.asp and give each forum a different application variable prefix, cookie prefix, and if you want to share 1 database you would also give each forum a different database table prefix.