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. Its 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: https://www.knot-dns.cz/