Hello fredguily,
You are correct, Active Directory does allow you to create an account without a first or last name. However, WebDir was designed to require the First and Last Name fields; because it auto-generates the user's Full Name, Display Name, User Logon Name, and pre-windows User Logon Name when creating the account. Turning off this feature would be considered a customization. If you would like more information on customization fees and services, please contact Imanami Client Services by calling 925-273-2909 or email: support@imanami.com. At this time, I have added the feature request to the WebDir wish list to be considered for implementation in the next release of WebDir (5.0).