- Can serve out A, MX, and PTR responses.

- Serves out a static list of NS records.

- Serves out a somewhat faked but acceptable SOA record.

- Adds additional A records for in-zone MX names.

- Adds additional A records and authoritative NS records for all given
  nameservers.

- All records have the same nameservers.

- Reads in 1 to 10 nameservers from environment variables NS0 through NS9.

- Benchmark:
  - Hardware/OS: PIII 500MHz, Linux 2.2.16, SCSI2U drives
  - Software: pgsqldns and postgresql on same server, remote dnsbench
  - Query mix: mix of 5 A queries
  - Response rate:
    - 1 client:  350/sec, 10% server idle time
    - 2 clients: 373/sec, 4% server idle time
    - 4 clients: 372/sec, 4% server idle time
  - Comparison with tinydns (same mix, client, server):
    - 1 client:  2388/sec, 50% server idle time
    - 2 clients: 3864/sec, 15% server idle time
    - 4 clients: 4125/sec, 4% server idle time
