This means the end of writing custom support code for each new application for features such as security, asynchronous communication, and object pooling. Many of these services are administered from a single Microsoft Management Console snap-in called Component Services. A Catalog object stores application attributes in the registry and RegDB databases, keeping duplicate settings in sync and presenting a unified logical view of the information. The Catalog also provides a transactional and scriptable interface so you can write your own substitution to the Component Services snap-in if you wish. Components can call different implementations of various services and not be bound to a single service implementation.
Interceptors act as a proxy to another object in another context, able to cross context boundaries.
Microsoft Message Queue, introduced with the Windows NT 4.0 Option Pack, allows interapplication and component communications, letting disconnected applications queue messages and transmit them when a network becomes available again. This means you can't count on a method executing immediately or expect to get an immediate response. If the client and server components have an active connection, the code executes immediately. If they are not connected, execution waits until the network connection is re-established. Queued components have enormous implications for enterprise application development, particularly for disconnected client applications and those running on personal digital assistants.