ADF allows you to create an extension or a plugin that will work with JDeveloper 11gR2. For example, we might create a plugin in JDeveloper that will allow the user to open the Model or ViewController project file in Notepad.
The extension development is based on a standard called Open Services Gateway Initiative (OSGI). More information about OSGI can be found at http://www.osgi.org/Main/HomePage.
You can download the Extension SDK from Oracle by going to Help | Check for Updates. The URL to download the Extension SDK is as follows:
http://www.oracle.com/ocom/groups/public/@otn/documents/webcontent/131167.xml#oracle.jdeveloper.esdk
The Extension SDK API URL is as follows:
http://docs.oracle.com/cd/E16162_01/apirefs.1112/e17493/toc.htm