DNS protocol implementation with client and server

 Twisted Names is both a domain name server as well as a client
 resolver library. Twisted Names comes with an "out of the box"
 nameserver which can read most BIND-syntax zone files as well as a
 simple Python-based configuration format. Twisted Names can act as an
 authoritative server, perform zone transfers from a master to act as
 a secondary, act as a caching nameserver, or any combination of
 these. Twisted Names' client resolver library provides functions to
 query for all commonly used record types as well as a replacement for
 the blocking gethostbyname() function provided by the Python stdlib
 socket module.