Hostupd is a very simple perl script, which makes use of the Net::DNS module, to assist in updating DNS records dynamically.
Here's a sample hostupd command which adds both A and PTR records:
hostupd add myhost myip
on complex environments, it might not autodetect the zone and server ip:
hostupd add -s mynameserver -z myzone myhost myip
The the last commit took place on 2002 (when I was a perl newbie, it shows..). Today, 7 years later (wahhh!), I've found and fixed an annoying bug by a adding a single line.