eduroam stands for education roaming and is an international cooperation between universities. It provides researchers, teachers and students easy and secure network access at the home university and when visiting an institution other than their own - with no changes to the computers configuration.
Is called KTHOPEN and is a "captive portal", that is when you connect to the network you get an IP-address - but to use the network you have to login. When you start a web-client (Internet Explorer, Firefox etc) you will be forced to the login page. All users that have KTH account are able to login. Guests have to order a login.