In many ways Congress is similar to ActiveDirectory (AD).
Both Congress and AD are cloud services whose main responsibility is policy.
Both Congress and AD are concerned with providing a single touchpoint for
policy across the cloud so that users may understand and control their cloud
from a holistic point of view.
Both Congress and AD support a policy language that includes abstractions
like groups that make it easy to express policies over large numbers of
servers, networks, users, files, etc.
Congress generalizes ActiveDirectory in several dimensions.
AD is primarily used for managing a collection of servers. Congress is
designed to manage any collection of cloud services. Congress does not
require any of its own code running on the services it is managing.
AD’s policy language provides a list of several thousand actions that the
policy controls (e.g. changing the screen saver). Congress provides a
high-level, general-purpose policy language where a policy controls which
states of the cloud are permitted (independent of which actions were
executed to achieve that state).
AD enforces policy by relying on the OS to prevent violations before they
occur. Congress makes no assumptions about the enforcement points it has
available; rather, once we add enforcement capabilities, it will prevent
policy violations when possible and correct them when not. And Congress
enables administrators to control the extent to which enforcement is
automatic.