<database, networking> A structured repository of information on people
and resources within an organisation, facilitating management and communication.
On a LAN or WAN the directory service identifies all aspects of the network
including users, software, hardware, and the various rights and policies
assigned to each. As a result applications can access information without
knowing where a particular resource is physically located, and users interact
oblivious to the network topology and protocols.
To allow heterogeneous networks to share directory information the ITU proposed
a common structure called X.500. However, its complexity and lack of seamless
Internet support led to the development of Lightweight Directory Access Protocol
(LDAP) which has continued to evolve under the aegis of the IETF. Despite its
name LDAP is too closely linked to X.500 to be "lightweight".
LDAP was adopted by several companies such as Netscape Communications
Corporation (Netscape Directory Server) and has become a de facto standard for
directory services. Other LDAP compatible offerings include Novell, Inc.'s
Novell Directory Services (NDS) and Microsoft Corporation's Active Directory.
The Netscape and Novell products are available for Windows NT and Unix
platforms. Novell Directory Services also run on Novell platforms. Microsoft
Corporation's Active Directory is an integral part of Microsoft's Windows 2000
and although it can interface with directory services running on other systems
it is not available for other platforms.
Direct Memory Access « directory « Directory Access
Protocol « directory service » Directory
System Agent » Directory User Agent » DirectX