Firstly, an introduction so you'll know what this is about:

A few days ago we posted an update to the script that installs

Hamachi is a zero-configuration virtual private network (VPN) application capable of establishing direct links between computers that are behind NAT firewalls without requiring reconfiguration (in most cases); in other words, it establishes a connection over the Internet that very closely emulates the connection that would exist if the computers were connected over a local area network.