Workspace Access Plugin Extension
This type of plugin extension allows you to contribute actions to the main menu and toolbars, create custom views, interact with the application workspace, make modifications to open documents, and add listeners for various events. It is the most useful and most commonly used plugin extension.
A Workspace Access plugin extension can also provide frameworks, allowing you to have a single add-on that provides both workspace-level extensions (independent of any given framework) and document type-specific frameworks. If the frameworks involve Java extensions (for example, custom dialog boxes or link text resolvers), they use the Java code for the Workspace Access plugin.
You can include frameworks with a Workspace Access plugin by declaring an "additional frameworks" extension in the plugin.xml file.