 LogMeIn Hamachi

LogMeIn Hamachi is a virtual private network (VPN) application written by Alex Pankratov in 2004.It is capable of establishing direct links between computers that are behind network address translation ("NAT") firewalls without requiring reconfiguration (when the user's PC can be accessed directly without relays from the Internet/WAN side); in other words, it establishes a connection over the Internet that emulates the connection that would exist if the computers were connected over a local area network ("LAN").