The Siphon Project is a passive network mapping software suite.
This software has the ability to map network information including
port information, operating system detection, topology mapping, 
vulnerability analysis and network usage statistics without
sending out a single packet. 

The Siphon homepage is located at:

	http://gravitino.net/projects/siphon/

Cryptographic signatures and checksums may be provided by 
the developers at the URL(s) above.  Wiretapped recommends
that users check these before use of the software/information.