Privman is a library that makes it easy for programs to use privilege
separation, a technique that prevents the leak or misuse of privilege
from applications that must run with some elevated permissions. The
Privman library simplifies the otherwise complex task of separating
the application, protecting the system from compromise if an error in
the application logic is found.

Applications that use the Privman library split into two halves, the
half that performs valid privileged operations, and the half that
contains the application's logic. The library uses configuration files
to provide fine-grained access control for the privileged operations,
limiting exposure in even of an attack against the application. When 
the application is compromised, the attacker gains only the privileges
of an unprivileged user and the specific privileges granted to the
application by the application's Privman configuration file.

WWW: http://code.google.com/p/privman/