MaraDNS is a
security-aware
DNS implementation. It can be configured as an authoritative DNS server or as a "recursive" DNS cache. Versions up to 1.0.xx have been released to the
public domain. Versions after 1.1.00 are
copyrighted but are distributed with a liberal
licence (a simplified
BSD licence without the advertising clause.)
MaraDNS homepage (http://www.maradns.org/)