DNSSEC (5)

• BIND 9 Administrator Reference Manual — BIND 9 9.20.26 documentation (bind9.readthedocs.io) reference
  authoritative and resolver setup, zone files, DNSSEC signing and validation, plus dig and named manpages
  DNS Network Diagnostic #
• Unbound - About (NLnet Labs) tool
  validating recursive caching resolver with DNS-over-TLS/HTTPS and QNAME minimisation, BSD licence
  DNS Privacy #
• Knot DNS (knot-dns.cz) tool
  Authoritative-only DNS server with IXFR, DDNS, rate limiting and automatic DNSSEC signing, GPL 3+
  DNS #
• Knot Resolver (knot-resolver.cz) tool
  caching validating resolver from CZ.NIC with modular features and DoH; GPL, free to download
  Caching DNS #
• DNSViz | A DNS visualization tool (dnsviz.net) tool
  Web visualiser for a zone's DNSSEC authentication chain and resolution path, flagging errors
  DNS Network Diagnostic #