Active Directory, 5th Edition

Chapter 20. Active Directory Lightweight Directory Services

Shortly after Microsoft released Windows 2000 Active Directory, developers and administrators started asking for a standalone Microsoft LDAP service that was similar to Active Directory, but without the overhead (e.g., DNS and FRS requirements, Group Policy, and other domain pieces like Kerberos and legacy SAM interoperability)—basically, something light and easy to set up, play with, and tear back down as required. While you can do this with Active Directory, there tends to be additional cleanup and configuration required, and things unrelated to the LDAP functionality can get confused and cause it all to malfunction.

In November 2003, shortly after Windows Server 2003 Active Directory was released, Microsoft released Active Directory Application Mode (ADAM) V1.0 to the Web. This was the product that the developers and administrators had been asking for: Active Directory Lite. ADAM allowed developers and administrators to play with Active Directory on Windows XP or Windows Server 2003 and newer servers without promoting the localhost to a full domain controller. The only DNS requirement is resolution of the hostname. There is no FRS, no Kerberos, no Group Policy, and no extra domain stuff. In fact, ADAM runs nicely as a regular Windows application that can leverage any Windows domain authentication or local machine authentication that is available, as well as offering up its own authentication that is completely application-specific. ...