389 Directory Server (formerly Fedora Directory Server) is a full-featured LDAPv3 compliant server. In addition to the standard LDAPv3 operations, it supports multi-master replication, fully online configuration and administration, chaining, virtual attributes, access control directives in the data, Virtual List View, server-side sorting, SASL, TLS/SSL, and many other features. The transactional Berkeley DB 4.2 is used as its data store and a full plug-in API allows developers to extend the the functionality of the server in many ways, and many of the core features of the server are already implemented using this API. The server is very mature, having started out as Netscape Directory Server.