The SLAPD (Standalone LDAP Daemon) and SLURPD (Stand-alone LDAP update replication daemon) originally evolved within the long-running project that developed the LDAP protocol. It was developed at the University of Michigan, and was the first Lightweight Directory Access Protocol (LDAP) software.
Today, many LDAP Server Implementations are derived from the same code base of the original SLAPD and/or evolutions of it.
University of Michigan
Tim Howes of the University of Michigan, Steve Kille of Isode Limited, Wengyik Yeong of Performance Systems International and Colin Robbins of Nexor authored the original LDAP specification. In 1993, initial implementations of the LDAP standard were made by Howes at the University of Michigan, in the form of LDAPD as a proxy for the Quipu X.500 directory and SLAPD.
Netscape Communications Corporation