4 Just so we don't forget the required features for an AD-compatible DNS server:
6 - Forwarding to other nameservers if we don't know the domain
7 - Additional record handling (especially in SOA records, but we'll want off of
10 - Symmetric Bind-style key handling (not strictly needed for AD, but needed for
11 integration to other name servers / tools)
12 - Command line tools that unix admins are used to
13 - Zone transfer support (XFER, IFER)
15 - Tests, tests, tests (probably based on python's dns implementation)