The NSE is a framework that runs code written in the programming language Lua with specific flags that the engine can parse. Lua is a lightweight, fast, and interpreted programming language—one that has the most fame for scripting user interfaces for computer games such as World of Warcraft—that has a similar syntax to other contemporary interpreted languages.

If you've ever seen code written in Python or Ruby, Lua won't seem too alien to you.

The preceding screenshot shows an Nmap script that identifies information about Bitcoins (written by Patrik Karlsson). Don't worry if you don't understand it yet—that's something we will cover in Chapter 7, Writing Nmap Scripts—but you can see that the code used to generate a relatively complex Nmap script looks very simple. This is the whole point of the NSE! Where security engineers and system administrators used to have to export Nmap results, find the information they are looking for and then use third-party tools to...