The Nmap Scripting Engine (NSE) is one of Nmap’s most powerful and flexible features. It allows users to write (and share) simple scripts to automate a wide variety of networking tasks. Those scripts are then executed in parallel with the speed and efficiency you expect from Nmap.
All existing scripts have been improved, and 32 new ones added. New scripts include a whole bunch of MSRPC/NetBIOS attacks, queries, and vulnerability probes; open proxy detection; whois and AS number lookup queries; brute force attack scripts against the SNMP and POP3 protocols; and many more. All NSE scripts and modules are described in the new NSE documentation portal.