Eclipse is extended through the use of extension points and the extension registry. The registry manages a list of extension points and a list of extensions. Although it is commonly used in OSGi runtimes such as Eclipse, the extension registry can be used outside of an OSGi runtime as well.
The first thing to understand in the registry is the terminology. An extension is a contributed functionality that is often found in the
plugin.xml file as an
<extension> element. The extension itself provides some configuration or customization that can be processed appropriately. An extension is like a USB device, such as a mouse or keyboard. For example, the new feed wizard was added ...