LDAP

   LDAP is the C language application programming interface (API)
   for the Lightweight Directory Access Protocol (LDAP). This
   API supports Version 3 of the LDAP API (LDAPv3), and includes
   support for controls, information hiding, and thread safety. It
   is available on OpenVMS Alpha only.
 

Additional information available:

Introduction    Data_Structures Error_Codes     Initializing    Session_Handles
Controls        Authenticating  Closing         Searching       Attribute_Value
Modifying_Entry Modifying_Name  Adding_Entry    Deleting_Entry  Extensions
Abandoning      Results         Errors          Search_Results  Encoded_ASN.1
Using_SSL