Security researcher Michal Zalewski has released a new version of a passive fingerprinting tool called P0f. The tool is designed to run on a variety of platforms, including Unix, Mac OS X and Windows. It has a number of functions that users can use to find out what kind of machines are connecting to their system, what they’re doing and whether they re lying about what they are. The newest version, v3, is in release candidate form, but is available for free download from the site.
Source: https://threatpost.com/researcher-releases-new-version-p0f-fingerprinting-tool-011012/76078/