I did a nmap scan on my raq:

Port State Service
21/tcp open ftp
22/tcp open ssh
25/tcp open smtp
80/tcp open http
81/tcp open hosts2-ns
110/tcp open pop-3
143/tcp open imap2
443/tcp open https
444/tcp open snpp
3000/tcp open ppp
3001/tcp open nessusd

Is it normal that port 81 is open...? What is it used for?

81 is used for the admin interface on a RaQ. It's another instance of Apache running with higher perms.

adam