OWASP Coraza WAF is a golang modsecurity compatible firewall library
Manage port forwardings via UPnP
A java PCAP and DPI library
360-FAAR Analyze FW1 Cisco Netscreen Policy Offline Using Config/Logs
Jateway is a general purpose TCP/IP connection proxy
Sonicwall Configuration File Reader
Personal firewall for linux desktop and android phone
Lomalarga is a VPN-like service based on SSH and Linux.