If you have problems you might need to download java, you can get it from http://www.java.com/en/download/index.jsp

Another option is to use cgiirc that lives at http://jungleist.vmlinuz.co.uk:10050/nurave-irc2/irc.cgi all it need's is a normal browser and so is probably your best bet if you have problems

Alternativly you can use an irc client, you'll need to connect to
server: jungleist.vmlinuz.co.uk
channel: #nu-rave
If you don't have an irc client....
For Windows, MIRC http://www.mirc.com/
For Mac, Colloquy http://colloquy.info/