Simple DNS Plus is a very capable and full featured DNS server, and it has plenty of options for expert users to tweak it just the way they want. It can easily be integrated with your web-site for ISP customer signup etc., or even a full web-based DNS solution, optionally serve DNS records directly from a SQL server, and also comes with a DHCP server plug-in, a DNS Look Up tool, and many other features. For more information, please visit http://www.simpledns.com.