NethernetWhois
NethernetWhois allows you complete power over all settings, has online admin, and only one line of code to edit. It is the easiest way to allow your customers to register domains via the Internet. It features: Unlimited Domain Registrations, Automated mailing of all parties involved, Users can either Register or Modify a domain, Registration information for registered domains is displayed, Support for SSL Ordering for enhanced security, Built in Optional Credit Card Processing, and basic Syntax, and more.