squidGuard - squidGuard is a URL redirector/blocker.
Cisco Umbrella - Cisco Umbrella is a cloud security platform that provides the first line of defense against threats on the internet.
E2Guardian - Web filtering solution
WebTitan - WebTitan is an advanced DNS based web content filter and web security layer that blocks malware, ransomware and phishing attempts as well as providing web content control. Cloud and gateway versions available.
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.
DNSFilter - DNSFilter offers DNS-Based Content Filtering & Threat Protection.