The latest version of Nmap can be downloaded from Softpedia
Nmap or Network Mapper, an open source tool for network exploration and security auditing, designed to rapidly scan large networks and single hosts, is now at version 6.25.This release of Nmap integrates all of the IPv4 OS fingerprint submissions since January, more than 3,000 of them, bringing the total to 3,946.
The latest fingerprints added to the application includes Linux 3.6, Windows 8, Windows Server 2012, Mac OS X 10.8, and a ton of new WAPs, printers, routers, and other devices, not to mention the first IP-enabled doorbell.
IPv6 OS submissions and corrections were also summited for integration and the developers even enabled support for IPv6 trace route using UDP, SCTP, and IPProto.
Last but not least, the Nmap Scripting Engine is now designed to use Lua 5.2 or 5.2.1 and not the previous version.
A comprehensive list of changes can be found in the official announcement.
Download Nmap 6.25 right now from Softpedia.