How can one run two or more Vibe.d web apps in the same computer?

Can some ports be used other than 8080? If not, how can one run multiple web apps on the same computer with a single IP address?

When I try other ports on my local machine, I get:

Failed to listen on 127.0.0.1:80
or
Failed to listen on 127.0.0.1:81
or
Failed to listen on 127.0.0.1:8008

The reason for this is I want to host three web apps in a single Linode box.