for questions related to SLAPD, a Standalone LDAP Daemon, a predecessor of the modern LDAP protocol
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.
Today, many LDAP Server Implementations are derived from the same code base of the original SLAPD and/or evolutions of it.