Okay I did some checking as I wasn't really familiar with this game. It turnes out that the authors website is no longer active (some add site has claimed the domain). That might also be why you can't connect to a server.

As for XProgger, he has made a clone of NFK some time ago. I dont know if he is somehow related to NFK, but judging by the posts in his thread, I do not think he is.

In any case, If you need more information I suggest you use this great piece of software, as it took me less than 2 minutes to get to the info I just posted.