Oracle ADF Essentials ( Core ADF framework) is now free to develop and deploy !!!
From Oracle site -
Oracle ADF Essentials is an end-to-end Java EE framework that simplifies application development by providing out-of-the-box infrastructure services and a visual and declarative development experience. Oracle ADF Essentials is free to develop and deploy.
Read the full story here: http://www.oracle.com/technetwork/developer-tools/adf/overview/adfessentials-1719844.html