Spinner makes it possible to easily have any number of virtual servers, bound to different ports and/or different network interfaces.

To add a new virtual server, focus on the Virtual Servers page (by clicking on the text, instead of unfolding it).

As you haven't added any configurations the page you come to should be empty. Click on [NEW VIRTUAL SERVER] to add a new one.

You will be promted for the name of the new virtual server. Enter it, and press return.

You will now be back to the Virtual Servers menu, which has a new entry - the one you just made.

You have now added a new virtual server, and it's time to configure it.