Certification of conformance with the Lightweight Directory Access Protocol (LDAP), a specification for accessing and creating directory information, addresses customers' desire for interoperable directory products. In doing so, it saves companies money and improves their ability to move information in a secure, reliable, and timely manner. This paper introduces the reader to the advantages and components of the third-party LDAP certification programs operated by The Open Group. It has been written by the Directory Interoperability Forum (DIF).