The thing that plugins plugin to!

Extension Point

A well defined place where new functionality and/or data can be contributed to an application.

Extension (aka Contribution)

An actual piece of functionality or data that is contributed (this is why extensions are often known as contributions). Think of ‘extension points’ as the ‘where’ and ‘extensions’ as the ‘what’.

Extension Registry

The place where (by default) all of the extension points and their associated extensions are stored.


In Envisage, a service is any object that a developer thinks is sufficiently useful to want to share it.

Service Registry

The ‘yellow pages’ style mechanism that is used to publish and look up services.


The mechanism for delivering new functionality to an application. A plugin can do 3 simple things:

  1. offer extension points

  2. make contributions to extension points (including its own)

  3. create and publish services

Plugin Manager

Finds, starts, and manages the plugins that make up an application.