“BIND version 9 is a major rewrite of nearly all aspects of the
underlying BIND architecture….”
“Compared to BIND 9.0, BIND 9.1 has a number of new features as
well as numerous bug fixes and cleanups.”
“BIND 9.1.0 also includes experimental implementations of a
number of DNS protocols extensions still under development in the
IETF. These include transparent processing of unknown RR types and
use of the EDNS “DNSSEC OK” bit to explicitly enable DNSSEC
processing in responses.”
“Cryptographic operations are now based on the OpenSSL library
instead of DNSsafe.”