Butterfly Web UI is a component based Java Web application framework. Like the rest of the Butterfly Components, Butterfly Web UI is extremely small and very flexible. Butterfly Web UI uses Butterfly Container internally, a state of the art dependency injection container. Using Butterfly Web UI, it is easy both to generate HTML for a Web browser or XML or JSON for a RIA frontend (Flex, JavaFX, Silverlight) or AJAX frontend. You also can easily create HTML layout templates that are reused throughout your Web application, so you don't have the layout hardcoded into every page. You can easily mix RIA and non-RIA Web application technology in the same Web application.
Sight is a Java Web framework built on top of J2EE technologies, and particularly on top of the servlet API. SightWF provides a simple programming model for building RIA applications. SightWF is initially designed to be deployed on Google App Engine, and can be run in a J2EE servlet container such as Tomcat.
Apache Click is a modern JEE Web application framework, providing a natural rich client style programming model. Apache Click is designed to be very easy to learn and use, with developers getting up and running within a day. It also supports automatic component rendering, client/server side validation, full localization, and multiple template engines (currently Velocity, JSP, and FreeMarker).
Werc is a minimalistic RESTful Web application framework and content management system. It follows the Unix "tool philosophy" and it is designed to be fast, simple, convenient, and easily extensible. It handles both small and big sites and has a flexible system for user and group permissions. All data is stored in plain text files that can be easily manipulated with standard tools, without using any databases or other external dependencies. Existing applications include a blogging engine with RSS/Atom feeds, a wiki system that can easily integrate pre-existing documents (can be enabled for any directory tree), and others.