While working at Sun Microsystems in 2003, Greg Lavender and Mark Wahl wrote a whitepaper providing an in-depth history of directory services, and a good technical overview of LDAP. That document is published here with permission.
At the time, Greg Lavender was Director of Engineering and CTO for identity management software at Sun Microsystems, and Mark Wahl was Senior Directory Architect. Before that, they had an esteemed history of directory services experience at Innosoft International, Critical Angle, and the ISODE Consortium. Mark was also the co-author and editor-in-chief of the primary LDAPv3 specifications (including RFCs 2251–2253) and several other LDAP-related RFCs and Internet Drafts.