NASL is a scripting language designed for the Nessus security scanner. Its aim is to allow anyone to write a test for a given security hole in a few minutes, to allow people to share their tests without having to worry about their operating system, and to guarantee everyone that a NASL script can not do anything nasty except performing a given security test against a given target. Thus, NASL allows you to easily forge IP packets, or to send regular packets. It provides you some convenient functions that will make the test of web and FTP server more easy to write. NASL garantees you that a NASL script: - will not send any packet to a host other than the target host, - will not execute any commands on your local system.