I wouldn't recommend having two asp.net applications sharing one set of files - I think there's a chance of locking problems and other maintenance issues. Jeremy - to answer your questions: - no, a new portal is nothing more than a couple of database records in the DNN tables, and a new folder under the /portals/ directory. The Url Rewriting component takes care of identifying which request belongs to which portal by matching the domain name against the list of domains in the PortalAlias table. Once it knows which portal, it then loads this into the request context, and all the other 'downstream' code knows which page, skin, modules etc to load. - you should be able to load mutiple certificates to a site. When you have two portals with different domain names, you have to configure IIS to 'respond' to those different domains. You can assign the different domains to different IP addresses on your server, and I'm pretty sure (though never tried) that you can assign more than one certificate to the DNN install website, one for each different IP address. It's a pretty clear choice in the end : either do one install with two portals, or two separate installs. Creating some type of hybrid sounds initially appealing, but eventually something will go wrong due to resource constraints, and you'll just need to go back to either two portals or two installs. The smart way is to follow the recommendation from the start and save yourself headaches down the track.