In Pictures: Top 10 security tools in Kali Linux 1...
Nmap is a free and open source utility for network discovery and security auditing which runs on every major operating system. Nmap is a command line tool and while basic functionality is straightforward in common with many sophisticated security tools there are more command line switches than the mind can comfortably encompass. Geeks abhor a vacuum so there is, of course, a front-end GUI called Zenmap which really makes using Nmap easy.
In Pictures: Top 10 security tools in Kali Linux 1.0.6