Introduction to System.DirectoryServices, Part 1The .NET Framework System.DirectoryServices namespace is a robust and flexible API for querying and manipulating objects in an LDAP directory, such as Microsoft's Active Directory. The System.DirectoryServices namespace contains several classes, many of which are built on top of ADSI (Active Directory Service Interfaces). If you are already familiar with ADSI, the learning curve for understanding the System.DirectoryServices classes will be pretty minimal.