NMap 6.01 has been released at http://nmap.org/download.html"Nmap ("Network Mapper") is a free and open source
(license) utility for
network discovery and security auditing. Many systems and network
administrators also find it useful for tasks such as network
inventory, managing service upgrade schedules, and monitoring host or
service uptime. Nmap uses raw IP packets in novel ways to determine
what hosts are available on the network, what services (application
name and version) those hosts are offering, what operating systems
(and OS versions) they are running, what type of packet
filters/firewalls are in use, and dozens of other characteristics. It
was designed to rapidly scan large networks, but works fine against
single hosts. Nmap runs on all major computer operating systems, and
official binary packages are available for Linux, Windows, and Mac OS
X. In addition to the classic command-line Nmap executable, the Nmap
suite includes an advanced GUI and results viewer
(Zenmap), a flexible data
transfer, redirection, and debugging tool
(Ncat), a utility for
comparing scan results (Ndiff), and a packet generation and response analysis tool (Nping)."Home page is at http://nmap.org/ Nmap is free to download and use. You can download the source and compile it yourself if you so require.
