Lightweight Directory Access Protocol
These pages are provided for historical reference only.
The LDAP software contained herein is out of date. We suggest
parties seeking open source, production quality LDAP software
The Lightweight Directory Access Protocol (LDAP) is a protocol for
accessing online directory services. It runs directly over TCP, and can
be used to access a standalone LDAP directory service or to access a
directory service that is back-ended by X.500.
A widely used implementation of LDAP was written at the University of
Michigan, where development was being supported by the National
Science Foundation under Grant No. NCR-9416667. The final release of
the U-M LDAP package is available as a compressed Unix tar file:
This software, and its documentation
which describes how to use the UM implementation to set up a
directory service and also inlcudes an overview of LDAP-based
directory service, is provided merely for historical reference.
Current software is available from
Some other related resources (not at UofM) include:
The University of Michigan LDAP implementation includes libraries for
writing LDAP clients, and it has been ported to many flavors of Unix
as well as to the Macintosh, MS-DOS, Microsoft Windows, and VMS.
These libraries are included with the UM LDAP implementation
There are several LDAP-related mailing lists that may be of interest:
- To join a general discussion and announcement list, send e-mail to:
The list is maintained by a listserver, so please inlcude the word "subscribe"
in either the subject or text of your message.
An online HTML archive of the ldap list was occasionally
updated; a more complete,
historical, archive is also available as one large text file.
- To join a very technical list where the LDAP protocol is discussed,
send e-mail to:
- To ask questions about or report bugs inthe U-M LDAP implementation, send e-mail
to the general discussion and announcement list,
There used to be a group of UM and Netscape people who would answer
questions sent to firstname.lastname@example.org and accept bug reports sent
to email@example.com. The UM employees no longer receive funding
for LDAP research and the Netscape people have become busy with their
own products. As a result, email to firstname.lastname@example.org
email@example.com only results in an automated message recommending
using the 'firstname.lastname@example.org' list for help.
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