How to deploy multiple applications to the same server with capistrano?
If your applications are just standalone applications that don't have dependencies on each other (i.e. you deploy them individually) then just deploy them with capistrano as you normally would.
By default capistrano will deploy to a folder such as /var/www/app_name so as long as all of the apps have a different name configured in their app_name.rb they will be blissfully unaware of each other.
You may need to be a little bit more careful with some of the services you may use, e.g. you may wish to namespace your memcache keys (or run separate memcache instances) so as to avoid clashes between apps.