Don't have
Java or is it blocked from loading via a script blocker or firewall/router? It won't load.
Port 6667/IRC filtered via a firewall/router? It won't load.
Just plain idiotic for not being able to load/run a simple javascript page? It won't load, well, at least run right, user error and all.
Though the chat system hasn't been updated in ages it should run fine without any type of maintenance on my side, I just went there and it loaded and connected without any issues; do you get an error? If so then I wouldn't have any problem in upgrading the darned thing, but only if there is a reason to do so.