PUBLIC MARKS with tags framework & "open source"

Sesame is an open source framework for storage, inferencing and querying of RDF data.

The OAICat Open Source project is a Java Servlet web application providing an OAI-PMH v2.0 repository framework. This framework can be customized to work with arbitrary data repositories by implementing some Java interfaces.

qooxdoo is a comprehensive and innovative Ajax application framework. Leveraging object-oriented JavaScript allows developers to build impressive cross-browser applications. No HTML, CSS nor DOM knowledge is needed.

With proper mark-up/logic separation, a POJO data model, and a refreshing lack of XML, Apache Wicket makes developing web-apps simple and enjoyable again. Swap the boilerplate, complex debugging and brittle code for powerful, reusable components written with plain Java and HTML.

Java to JavaScript Compiler & J2S SWT Library. Java-to-JavaScript compiler, provide general java.lang.* and java.util.*, and an extra UI widget library. This is very similar to Google Web Toolkit, except that GWT requires to use specific widgets wheras J2S uses standard SWT widgets. And J2S as an Eclipse License.

ZK is an open-source Ajax Web framework that enables rich user interface for Web applications with little programming. With event-driven components and a markup language, developing is as simple as programming desktops and authoring HTML.

MooTools is a compact, modular, Object-Oriented javascript framework designed to make writing extensible and compatible code easier and faster. MooTools lets you get the job done efficiently and effectively.

Java Open Source workflow engine based on XPDL

The ActiveBPEL engine is an Open Source implementation of a BPEL engine, written in Java. It reads BPEL process definitions (and other inputs such as WSDL files) and creates representations of BPEL processes. When an incoming message triggers a start activity, the engine creates a new process instance and starts it running.

ZK is an AJAX/XUL Web framework designed to enable Web applications to have both rich user experiences and a simple programming model. It includes an AJAX-based event-driven engine to automate interactivity and a rich set of XUL-based components.

The Echo Web Framework is for developing web-based applications that approach the capabilities of rich clients. Echo2 removes the developer from having to think in terms of "page-based" applications and enables him to develop applications using the conventional object-oriented and event-driven paradigm for user interface development. Knowledge of HTML, HTTP, and JavaScript is not required. Applications may be hosted using any Java servlet container. Echo2, like its predecessor, is open-source software distributed under the terms of the Mozilla Public License (or, if preferred, the GNU LGPL License).