Framework Java Extensibility Guide
Advanced users can extend the functionality of custom frameworks and Author mode. The Oxygen SDK is also available to provide developers the ability to extend the functionality of Oxygen XML Author.
You can add extensions to your custom
framework (document type) by using
the Extensions tab from the Document
Type configuration dialog box.
Note: It is
possible for a plugin to share the same classes with a framework.
For further details, go to How to Share the Classloader Between a Framework and a Plugin.