OWASP Coraza WAF is a golang modsecurity compatible firewall library
Anti Spam SMTP Gateway
IPFIRE Firewall for ARM architecture (OrangePi)
OWASP ModSecurity Core Rule Set (CRS) Project
Prevent and Protect Your HTML5 Video, Music , Audio From Download Free
PeerGuardian - a privacy oriented firewall application
Easy to use firewall for linux beginners.
Detect Flooder IPs, Reduce Attack Surface against HTTP Flood Attacks