The whole architecture is divided into 2 areas:
Netbeans Platform RCP is a generic desktop application developed by Netbeans Development Teams. This platform provides comprehensive support for building rich client applications such as menus, document management, settings and so forth. Instead of writing the same code over and over again, write modules to implement what you need, bundle them up with the NetBeans Platform, and you have a beautiful, branded, cross-platform application. NetBeans based applications are write-once, run-anywhere. You get prebuilt components for free and you solve common problems by reusing, mixing and matching them. Use the platform and the modules you develop as the basis for multiple applications that share common logic. The NetBeans Platform is a solid foundation and set of standards for clear design. More info...
Citra FX is build on top of Netbeans Platform RCP. It acts as Netbeans Module (Plugins) that extends Netbeans Platform RCP. Citra FX itself is divided into several modules:
These code samples provided for developers to learn how to develop plugins for Citra FX.
You may also visit developers blog at http://blogs.kiyut.com/tonny/ for some information related with Citra FX Photo Effects development.
Note: The blogs also contains other unrelated things.