Nmap started from humble beginnings. Unlike the commercial security tools that are released today, the very first Nmap was only about 2,000 lines of code—and was released in 1997 in issue 51 of Phrack, a hacker "zine" that was started in 1985. Nmap's timeline is a fascinating one, and its growth has been phenomenal. The general timeline of Nmap development is as follows:
At the time of release, Nmap did not have very many features; in fact, it was bare bones. There was no version number attached to this release of Nmap because the developers did not plan to release any future versions. Nmap was designed only to scan for open ports on a target machine, and only worked when run from a Linux host and compiled with gcc.
Only four days after the initial release of Nmap, though, a slightly improved version was released (also through Phrack)—version 1.25. It was becoming very clear, even in the infancy of the now-famous tool, that there was an extremely high demand for a high-performance port scanner. Although there had previously been ways to detect open ports, Nmap made it straightforward to assess a third-party host over the Internet or across a local network. The hacker community was intrigued.
By March 1998, about six months after the initial Nmap release, the scanner had become the de facto port scanner of the underground hacker community and blossoming information security industry. Renaud Deraison asked permission to use the scanner code in a new vulnerability assessment engine he was creating, and (after receiving permission) Nmap scanning technology became integrated with the very first version of Nessus.
By September 2003, when Nmap 3.45 was released, there had been many major changes to the project. Fyodor, the primary developer, is now working on maintaining Nmap full-time. The tool has many new features—such as service detection, OS detection, timing configuration, and optimization flags (all of which will be covered later in this book)—and has truly reached a state of maturity.
In December 2006, one of the most important aspects of the Nmap project was integrated into all Nmap builds: Nmap Scripting Engine (NSE). The NSE allows users of Nmap to write their own modules (in a programming language called Lua) to trigger on certain ports being open, or certain services—or even specific versions of services—found listening. This release allows the elevation of Nmap from a simple networking tool to a fully robust and customizable vulnerability assessment engine, suitable for a wide variety of tasks.