Knot DNS is a high-performance authoritative-only DNS server
which supports all key features of the domain name system
including zone AXFR and IXFR, DDNS and DNSSEC.

Key features:

 - Open source

 - High-performance, multi-threaded, and mostly
   lock-free implementation which scales well on SMPs

 - Object-oriented design

 - Support for all important DNS protocols:
     - Full and incremental zone transfers
     - EDNS0 and DNSSEC extensions, including NSEC3
     - NSID


WWW: http://www.knot-dns.cz/