The Present State of Directories

The need for large-scale directories, high connectivity between remote sites, and availability of an open and extensible programming interface pushed vendors like Microsoft into supporting LDAP and creating directory solutions based on it. Netscape, led by some of the LDAP developers from the University of Michigan, pushed its Netscape Directory Server product. Novell, which had developed a proprietary network directory called Novell Directory Services (NDS) in 1990, started to use LDAP and, eventually, some X.500 features. Microsoft implemented LDAP server support in some of its application products, notably Exchange Server 5 and Microsoft Site Server 3. Exchange 2000 Server, the latest version of Exchange, replaced its own directory structure with Active Directory. Many products incorporate support for accessing LDAP-based directories, including major e-mail applications such as Microsoft Outlook and Lotus Notes. Windows ships with a simple address book application that supports LDAP-based directories.

The trend in network directories is toward consolidating separate application directories and network operating system directories, while providing tight integration with the underlying operating system. This integration promises a reduced workload for network administrators and a better experience for the end user. It also opens opportunities for developers to create a new breed of network application. The data stored in the directory becomes universally available and is easily managed. Developers are freed from implementing their own database storage and security methods and can concentrate on the functionality of the networked application.