pluggable authentication module (Unix) (PAM)

Pluggable Authentication Modules (PAM) are libraries for integrating user authentication.

PAM modules are programming interfaces( API) for making programs and services independent of the underlying authentication schemes. In addition, PAM modules are also used for user account management, session management and password management. The uniform PAM programming interface (PAM API) has the advantage that the authentications for the individual applications do not have to be rewritten. The authentication modules can be assigned directly to the individual services. This means that the authentication data for all services can be stored centrally and changed centrally.

In addition to the PAM modules for Unix, there are those for AIX, Solaris, Linux, Mac OS X and various other operating programs.