Looking Ahead

Understanding and Deploying LDAP Directory Services > 2. A Brief History of Directories > Application-Specific and Special-Purpose Directories

<  BACK CONTINUE  >
153021169001182127177100019128036004029190136140232051053055078209005198133012153121043

Application-Specific and Special-Purpose Directories

In this section we discuss directories that are tied to a specific application (or to a tightly integrated suite of applications). These directories are distinguished from other, more general-purpose directories (such as LDAP directories) by their tight integration with specific applications and their use of proprietary interfaces and protocols. Typically, it is difficult or impossible to use these directories with directory-enabled applications they were not designed to support.

Application-Specific Directories

In the early 1990s, application-specific directories entered the mainstream (although they existed in various forms for many years before then). Application-specific directories are typically embedded in electronic mail and groupware products and are intended to serve the needs of only one application or a small suite of applications. The design of these directories is often driven by the user interface requirements of email or groupware applications. Examples of these directories include the following:

  • The IBM/Lotus cc:Mail Directory

  • The IBM/Lotus Notes Address Book

  • The Novell GroupWise Directory

  • The Microsoft Exchange Directory

  • The UNIX sendmail /etc/aliases file

Most of these application-specific directories are still sold and used today. Over time, they have become somewhat less proprietary in that most of them now provide LDAP client access. Typically, the LDAP support is second-rate and accomplished through gateways that are retrofitted to the existing service. By their very nature, application-specific directories tend to be hard to extend for use by other directory-enabled applications.

Centralized Internet Directories

A second category of special-purpose directories has recently emerged since the explosion of Internet content services: large, centralized directories that hold information about Internet users. Some of the best known directories are

  • AT&T Labs' AnyWho Directory (http://www.anywho.com)

  • Bigfoot Directory (http://www.bigfoot.com)

  • Yahoo!'s Four11 Directory (http://www.four11.com)

  • Switchboard Directory (http://www.switchboard.com)

  • WhoWhere? Directory (http://www.whowhere.com)

These directories often acquire this information about users from a combination of Usenet News postings and voluntary registration. Typically, the centralized Internet directory services also provide a directory based on public telephone directory information and are quite popular with users who are looking for lost loves or their old high school buddies .

Now that Internet email clients and Web browsers can act as LDAP clients , many of these directories support access over LDAP in addition to their primary HTML form-based interfaces. Like most Internet content providers today, they fund their services through the sale of advertisements that appear at the service access points or within search results.



Understanding and Deploying LDAP Directory Services,  2002 New Riders Publishing
<  BACK CONTINUE  >

Index terms contained in this section

application-specific directories 2nd
centralized Internet directories 2nd
directories
          history of
                    application-specific directories 2nd
                    centralized Internet directories 2nd
history of directories
          application-specific directories 2nd
          centralized Internet directories 2nd

2002, O'Reilly & Associates, Inc.



Understanding and Deploying LDAP Directory Services
Understanding and Deploying LDAP Directory Services (2nd Edition)
ISBN: 0672323168
EAN: 2147483647
Year: 1997
Pages: 245

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net