DNSwitness is a set of various programs to analyze DNS (Domain Name System) data. 

The programs are;

* DNSdelve, an active measurement framework. It uses a list of domains
  (for instance all the subdomains of a TLD) and can query them for
  various things such as the presence of SPF records, the IP addresses
  of the name servers, etc

* DNSmezzo, a passive measurement tool. Located in front of a name
  server (recursive or authoritative), it parses the data and put them
  in a SQL DBMS for easier analysis.

Maintainers: AFNIC (registry of .fr), [email protected]

Licences: see individual programs but typically free software.

http://www.dnswitness.net/