NxFilter is described as 'freeware web filtering software controlling user activity on Internet. You can monitor Internet usage in your network and block user request for websites with NxFilter'. There are more than 50 alternatives to NxFilter for a variety of platforms, including Windows, Online / Web-based, Android, iPhone and iPad. The best alternative is 126.96.36.199, which is free. Other great apps like NxFilter are OpenDNS (Freemium), OpenNIC (Free, Open Source), Quad9 (Free) and Qustodio (Paid).
188.8.131.52 from CloudFlare is the fast and private way to browse the Internet. It is a public DNS resolver, but unlike most DNS resolvers, 184.108.40.206 is not selling user data to advertisers. The implementation of 220.127.116.11 makes it the fastest resolver out there.
SafeDNS provides sophisticated cloud-based and software solutions for web content filtering which increase users' safety online by blocking botnets, malware and phishing resources, filter out most advertising and content users consider inappropriate.
e2guardian is an Open Source web content filter, It filters the actual content of pages based on many methods including phrase matching, request header and URL filtering, etc. It does not purely filter based on a banned list of sites.