Customer Service, who cannot seem to get the concept of maintaining forward and reverse mapping. I run BIND 8 on Solaris, so something that runs under Solaris (not MickeySoft) is preferable. Both web and local shell database modification is definitely a plus. I'd rather not reinvent the wheel by programming this myself.
We do it with perl and Sybase on Linux, with a web interface (perl) for customer service people. hardest part was all the sanity checks for stupid data entry errors ie: adding/delete trailing periods, standardizing MX values... a small perl script runs every hour with more sanity checks, then dumps out new text files for named to read. Side benefit: trusted competent customers (and yes, they do exist) get certain records and fields available for themselves to edit/change/delete. Ours is to integrated into too may other things to be useful by itself, but the DNS side was a solid weekend of coding: about 20hrs. but made my life easier and harder (I liked hand editing text files).