- Highly scalable and extremely fast identification of the operating system and software on both endpoints of a vanilla TCP connection – especially in settings where NMap probes are blocked, too slow, unreliable, or would simply set off alarms.
- Measurement of system uptime and network hookup, distance (including topology behind NAT or packet filters), user language preferences, and so on.
- Automated detection of connection sharing / NAT, load balancing, and application-level proxying setups.
- Detection of clients and servers that forge declarative statements such as X-Mailer or User-Agent.
The tool can be operated in the foreground or as a daemon, and offers a simple real-time API for third-party components that wish to obtain additional information about the actors they are talking to.