DNS Balance is a load-balancing DNS server which:

o Does dynamic load balancing.
o Can answer the most proper resolution based on the client's IP
  address.
o Implements "A" record lookups only.  This would be good for
  security.

This (FreeBSD) version differs from original in the following:
- It works as a daemon
- Has ability to write messages to logfile
- Can save it's PID

WWW: http://www.netlab.is.tsukuba.ac.jp/~yokota/izumi/dns_balance/