To quote from the Nmap website, "Nmap ('Network Mapper') is a free and open source (license) utility for network exploration or security auditing. Many systems and network administrators also find it useful for tasks such as network inventory, managing service upgrade schedules, and monitoring host or service uptime."

Ever since the first release in 1997, Nmap has been the scanning tool of choice for network professionals and has grown in features and support ever since then.

Version 5.00 includes almost 600 improvements since the last major release – the five major highlights, as identified by the Nmap team, are:

Ncat is a universal tool for data transfer, redirection and debugging.  Previously available as an add-on since v4.85, Ncat is now fully integrated into the distribution package.

The Ndiff scan comparison tool aids in the comparison of Nmap scans; taking two Nmap XML output files and identifying the differences between them.

Performance improvements.  Nmap itself has had some major performance improvements based, amongst other things, on extensive Internet scanning to identify likely open ports.  Additionally, team members spent considerable time optimising the core algorithms leading to a standard "benchmark scan time" improvement from 1879 seconds to 1321 seconds.

Officially published on January 1st 2009, "Nmap Network Scanning," the book about Nmap by its original author Gordon "Fyodor" Lyon, reviewed here was written, as Fyodor explains, to "to share everything he has learned about network scanning during more than a decade of Nmap development."  Surprisingly, the book was briefly Amazon's No. 1 best seller soon after release.

Finally, the Nmap Scripting Engine (NSE) allows users to write simple scripts to automate a wide variety of tasks.  Such scripts can be executed in parallel to ensure maximum speed and flexibility.

Read on for further highlights in the new release.