iptables script in only one file
Free UTM appliance: firewall, VPN, WAF and antivirus in one ISO.
OpenBSD based firewall distribution
ipset set listing wrapper script
Programmable completion code (bash) for ip[6]tables (netfilter.org)
Open source voucher management / hotspot system
bash programmable completion for conntrack-tools (netfilter.org)
Programmable completion code (bash) for ipset (netfilter.org)
network control and reporting