Colin Robbins has published on his blog a “Prehistory of LDAP“, which describes some of the origins of the standard.
All of this predates my involvement with LDAP, directory servers and even X.500, but I feel related to it, since the names, projects or people, he mentions are familiar to me and I had the chance to meet or even work with some of them.
Anyway, for the curious who want to understand the roots of LDAP, it’s definitely worth reading.
Ludo Sketches 
Thank you for the mention.
You’re welcome. Your article brought back good memories.