Implementing Directory Services

Directory Access Protocol (DAP): A protocol that is included in the X.500 directory standard from 1988 

Directory System Protocol (DSP): A protocol that is included in the X.500 directory standard from 1988

Directory Information Shadowing Protocol (DISP): A protocol that is included in the X.500 directory standard from 1988

Directory Operational Bindings Management Protocol (DOBMP): A protocol that is included in the X.500 directory standard from 1988

Lightweight Directory Access Protocol (LDAP): An open industry-standard protocol for accessing and maintaining directory services; the most popular open-source alternative to the DAP

Active directory (AD): The Microsoft alternative to directory services that offers customization and added features for the Windows platform 

OpenLDAP (lightweight directory access protocol): An open source and free directory service

Active directory users and computers (ADUC): The client tools that are used for accessing and administering a directory server