See http://www.corpit.ru/mjt/rbldnsd.html for description.
Older text follows. I need to figure out how to organize
all my www stuff... ;)
Here you'll find a tiny DNS daemon, rbldnsd, which
is designed especially to serve DNS-based blocklists
such as relays.osirusoft.com, dsbl.org, ordb.org,
rfc-ignorant.org and many others. This is extremly
fast daemon - it outperforms both bind and DJBDNS
greatly. It has very small memory footprint.
Currently (2002-11), machine as small as i486-100
with 32Mb memory can be DNS server for all zones
of relays.osirusoft.com just fine. Compare this
with requiriments for bind - 256Mb memory and 400MHz
PPro or higher machine.
On PII-233 machine and with relays.osirusoft.com
zones, it performs as many as 3500 requests per
secound - limited by machine's networking support
only, requires less than 2.5Mb memory to operate,
and takes 7 secounds to (re)load all zones.
The daemon can serve both IP-based and name-based
blocklists (with example of last being rfc-ignorant.org).
Unlike DJB's rbldns, it has ability to specify individual
values for every entry, and can serve as many zones on
a single IP address as you wish.
Input format is very simple and far more sutable for
such a task compared to one of full-featured bind.
It is released under GPL license version 2 or any
later version.
Enjoy.
-- Michael Tokarev, mjt {at} corpit {dot} ru.