Nmap 2.53 – Nmap v2.53 is a utility for network exploration or security auditing. It supports ping scanning (determine which hosts are up), many port scanning techniques (determine what services the hosts are offering), and TCP/IP fingerprinting (remote host operating system identification). Nmap also offers flexible target and port specification, decoy scanning, determination of TCP sequence predictability characteristics, sunRPC scanning, reverse-identd scanning, and more.
You can download it from the following link: https://packetstormsecurity.com/files/download/17813/nmap-2.53.tgz
Source: https://packetstormsecurity.com/files/17813/Nmap-Scanning-Utility-2.53.html