E2Guardian - Web filtering solution
ufdbGuard - URL filter for the Squid web proxy
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.
NaaS - Nudity-detection as a service run on solar powered Rasp Pi's
Qustodio - Free parental control software. Monitor and track your child's online activity. Block dangerous sites and protect kids from online bullying.
uMatrix - uMatrix: A point-and-click matrix-based firewall, with many privacy-enhancing tools.