Overview #Active Directory Lightweight Directory Service or AD LDS, formerly known as Active Directory Application Mode (ADAM), is a light-weight implementation of Microsoft Active Directory. AD LDS is capable of running as a service on computers running Microsoft Windows Server.
AD LDS shares the code base with Active Directory and provides the same functionality as Active Directory, including an identical API, but does not require the creation of domains or domain controllers.
Like Microsoft Active Directory, AD LDS provides a Data Store for storage of directory data and a Directory Service with an LDAP Directory Service Interface. Unlike Active Directory, however, multiple AD LDS instances can be run on the same server.