Insecure.Org is pleased to announce the immediate, free availability of the Nmap Security Scanner version 4.00 from http://www.insecure.org/nmap/.
Nmap ("Network Mapper") is an free open source utility for network exploration, administration, and security auditing. It uses IP packets in novel ways to determine which hosts are available online (host discovery), which TCP/UDP ports are open (port scanning), and what applications and services are listening on each port (version detection). It can also identify remote host OS and device types via TCP/IP fingerprinting. Nmap offers flexible target and port specifications, decoy/stealth scanning for firewall and IDS evasion, and highly optimized timing algorithms for fast scanning. Nmap runs on all popular operating systems, including Linux, Windows, Mac OS X, FreeBSD, Solaris, and OpenBSD. Download command-line or graphical versions of Nmap and its documentation from Insecure.Org.
Nmap has undergone many substantial changes since our last major release (3.50 in February 2004) and we recommend that all current users upgrade. Here are the most important improvements made in the 36 intermediate releases since 3.50 (See the ChangeLog for a much more detailed list):