While many canned security tools are available on this site for handling common tasks, scripting languages allow you to write your own (or modify existing ones) when you need something more custom. Quick, portable scripts can test, exploit, or even fix systems. Archives like CPAN are filled with modules such as Net::RawIP and protocol implementations to make your tasks even easier. Many security tools use scripting languages heavily for extensibility. For example Scapy interaction is through a Python interpreter, Metasploit modules are written in Ruby, and Nmap's scripting engine uses Lua.