Thanks for letting us know. The FQaota.net domain was moved from one server to another some time ago and it wasn't noticed that this problem was created. I fixed it coming in as a custom 404 error but it still doesn't work as some dependency that the CGI script uses is missing.
I am a bit tired right now so I am putting this off until tomorrow (or maybe even the next day as this is really old and not all that useful). I haven't decided if I should fix the FQaota.net URL or change the link to point to one that works.
Until I do,
https://www.futurequest.net/dns/ works and is that program.
It really doesn't look all that useful to me. It actually looks like something I should just delete. If you have a case that looks interesting and might change my mind feel free to tell me. Frankly, it just seems to me like a cause of confusion as to what *.gtld-servers.net is.
Those servers are the pool of servers (at least for US top level domains) that the root servers (the core DNS servers of the internet) tell you to ask for NS records on registered domains. IOW, if your domain is registered to our DNS servers *.gtld-servers.net are the pool of servers that tell clients to ask our servers how to get to your domain.