GitHub repository: summercms/pwnat
Description: The only tool and technique to punch holes through firewalls/NATs where both clients and server can be behind separate NATs without any 3rd party involvement. Pwnat uses a newly developed technique, exploiting a property of NAT translation tables, with no 3rd party, port forwarding, DMZ, router administrative requirements, STUN/TURN/UPnP/ICE, or spoofing required.