ContentBarrier - ContentBarrier is a Mac parental control program that empowers the guardians to make a shield confine the youngster from getting to the wrong and grown-up web content.
Qustodio - Free parental control software. Monitor and track your child's online activity. Block dangerous sites and protect kids from online bullying.
Pluckeye - Pluckeye is a filter that bolsters self-control on the Internet.
Norton Family - Symantec provides security products and solutions to protect small, medium, and enterprise businesses from advanced threats, malware, and other cyber attacks.
K9 Web Protection - This also contains the feature “Blacklist Without Password” which allows non-admin users to add sites to the “Always Block” list without requiring the K9 admin password.
NxFilter - Best performance. You don't want to slow down your network by installing a network security software. NxFilter is a light-weight DNS filter. It doesn't cause any latency issue in your network.