Jspx is free by all means. No charges for anything. Support is also free. You can download the source code of jspx and the sample demo projects and use them they way you like. You may change, use, redistribute, sell and educate in any way you like. You are not obligated to anything. We love open source and we support open source.
Jspx is using standard HTML tags to create dynamic web applications. The basic knowledge of HTML and java would give you a perfect jump into Jspx. Check out the getting started page to see what is need to turn on jspx world. The live demo also takes you step by step to go through the marvelous features.
Based on modern web technologies (JQuery, Twitter Bootstrap, JQuery UI, JQuery plugins) You can use it to create modern web apps. Jspx controls and components are built using these modern frameworks giving it a modern touch. The demo apps specially jspx-demo3 is based on these modern framework.