DNS implementations

[Johnny Fribert Lauridsen]

Someone asked for a list of implementations,  and I could not see an answer.
I got this from Mr. DNS (as I was asked by a customer of mine, I asked Mr. DNS):

JEEVES (Paul Mockapetris)
lbnamed (Roland Schemer)
QuickDNS (Men and Mice)
MacDNS (Apple)
NonSequitur
KA9Q
Dents (http://www.dents.org/)
dnscache/tinydns (http://cr.yp.to/dnscache.html)

See http://www.dns.net/dnsrd/docs/exotic.html for more.

Mr. DNS
Acme Byte & Wire
mr-dns at acmebw.com
www.acmebw.com/askmr.htm

and then:
Microsoft DNS,
BIND/ISC
AIC/CNR

Are there others?  For example - are the mainframe implementations in IBM MVS and IBM VM also ground-up
implementations?
Johnny