The engine is the set of classes that supports or implements the Restlet API. Since version 2.0, the Restlet API and Engine have been merged in a single “org.restlet.jar” file.

This separation has however stayed conceptually between the classes that are expected to be used by Restlet API users while developing their applications and the one that power this API and provide extensibility those additional connectors, authenticators and so on.

Internal connectors

In addition to supporting the Restlet API, the Reslet Engine includes a set of internal connectors that can be further extended or replaced through extensions.