A portscanner using the ip.id method described by antirez on bugtraq on dec 15 1998. First public port scanner (that I'm aware of) was published on bugtraq on dec 3 1999. This program was made public as a response to that on dec 4 1999. The scanner does not directly contact the target host and is therefore practically untracable. Requires libnet and libpcap.
Default is to send null packets for echo:ing, some firewalls block them. Override with -F<flags>
Lots of options. All nice.
Use -e instead of -o 256 if silent host is a windows box