[fleXive] is a JavaEE 5 open source (LGPL 2.1 or higher) framework for the development of complex and evolving (web-)applications. It speeds up development by easing many tedious and repetitive programming tasks and helping to keep your application(s) flexible during the development-cycle and in production.
Based on the latest industry-standards like EJB 3, JSF, etc. [fleXive] should be your choice for building up your own new application.
JSF Flex goal is to provide users capability in creating standard Flex components as JSF components. So users would create the components as normal JSF components and the project will create the necessary SWC, SWF files and etcetera and link the values of the components back to the managed beans using JSON+Javascript and Actionscript. {standard Flex components has been open sourced through MPL license}
Currently many of the standard rich flex widgets (buttons, sliders, inputs [richTextEditor, textArea, ...], progressbars, colorpickers, various panels [accordion, tabBar, ...], and etcetera) have been written as intention of support.
Exadel Fiji
Exadel Fiji is an extension to JavaServer Faces to fully encapsulate Flex.
Exadel Fiji extends JSF by allowing the use of Flex with JSF components and within a JSF page. When using Fiji Flex components, developers can use Flex with the same familiar JSF component-based approach to building user interfaces.