Ever since Demon was my first true ISP (AC – After CIX) back in the days of MS-DOS, Trumpet Winsock (Microsoft Windows 3.1) and Mosaic, I’ve always used Demon’s web-based Internet Tools, (DNS info, whois etc) since to this very day, so I was a bit confused and started to panic, when they had changed the website, but they’ve still kept the tools available now at this URL (web link for people that don’t know what a URL is!).
http://knowledgebase.demon.net/article/internet-tools.html
If you don’t know what they do, there probably not for you!