Nmap is Hollywood’s most famous “hacking” tool that has featured on numerous blockbusters. It was originally written to find hosts in a network thus creating a map of the network. Nmap does this by sending some unique packets and analysing the response received. Over the years, Nmap has grown tremendously and can now figure out the operating system, services with their versions and other statistics like presence of a firewall and uptime of the machines it scans.
Version 6 of Nmap was recently released after almost three years of active development and boasts a more powerful Nmap Scripting Engine, over 250 new scripts, full IPv6 support and improved scan speeds among many other improvements.