DNS control tools

[Steve Camp]

Someone is potentially interested in leasing a domain name from me.
One of the technical points is DNS control.  What DNS tools exist that
would allow me to maintain the DNS servers, but let this party login
and administer DNS entries.  I'm thinking along the lines of some sort
of web-based tool.  A user would login / authenticate themselves, but
the tool would limit the domains they could manage in some fashion.

Regards,

--
Steve Camp
steve at camp.com