An object-oriented programming interface to Active Directory of Microsoft Windows 2000. More generally, a set of interfaces built on the Component Object Model (COM) that lets applications work with various types of directories using a single access method. Active Directory Service Interfaces (ADSI) was formerly known as OLE DS.
ADSI works by abstracting the capabilities of directory services from different network providers to present a single set of interfaces for managing network resources in a distributed computing network. ADSI provides a simple, open, functionally rich, and scriptable method for interfacing with any directory service, independent of the vendor.
ADSI is built on the Component Object Model and consists of two types of COM objects (directory service leaf objects and directory service container objects) that clients can manipulate with interfaces. ADSI providers are used to implement these objects and their interfaces. Each object in a given namespace is identified using a unique name. For example, file system objects can be specified using their absolute path, while directory objects are usually specified using their X.500 address. However, ADSI is flexible enough to handle any naming system used by third-party vendors’ directory service implementations.
ADSI can be used by programmers and administrators to create directory-enabled applications using tools such as Microsoft Visual Basic or Microsoft Visual C++. ADSI supports the Lightweight Directory Access Protocol (LDAP) C API defined in Request for Comments (RFC) number 1823, which specifies a low-level interface for C language programming and provides support for the Messaging Application Programming Interface (MAPI) so that legacy MAPI applications will work with Active Directory.