As developers of .NET apps we all know that ASP.NET and Domain Controllers
don't mix well (though you can get them to somewhat work). However, we
still have a need to develop against AD (Active Directory). The following
link will allow you to download many goodies for Win2003 including ADAM:
Active Directory® Application Mode (ADAM) is now available for
download. Organizations, independent software vendors, and developers who want
to integrate their applications with a directory service now have an
additional capability within Active Directory that provides numerous
benefits.
http://www.microsoft.com/windowsserver2003/downloads/featurepacks/default.mspx