Which application supports centralized user authorization and directory services in Linux?

OpenLDAP is a widely used open-source implementation of the Lightweight Directory Access Protocol (LDAP) that supports centralized user authorization and directory services in Linux environments. It allows administrators to manage user accounts and related information in a central repository, making it easier to control access and provide authentication services across multiple systems within a network.

This capability is especially important in environments where managing individual user accounts across different systems can be cumbersome and inefficient. OpenLDAP enables organizations to maintain a single source of truth for user credentials and attributes, leading to better security practices and streamlined administrative tasks.

While NIS+ can provide similar functionalities, it is less commonly used in modern systems due to its limitations compared to LDAP's flexibility and standards-compliance. Active Directory is primarily a Windows-based system, although it can interact with Linux to some extent. LDAP Explorer is a tool for browsing LDAP directories rather than a directory service application itself. Thus, OpenLDAP stands out as the most appropriate choice for centralized user authorization and directory services on Linux.