Free UTM appliance: firewall, VPN, WAF and antivirus in one ISO.
Active Directory Domain Controller built on Rocky and Samba4.
An iptables IPv4 firewall and traffic shaping program
OPTOSS Next Gen Network Management System (NG-NetMS)
Programmable completion code (bash) for ip[6]tables (netfilter.org)
Tools to help you control IT systems and escape their control over you