Almond Java Application Framework is an easy to use Swing based framework for Java applications. Almond is very much inspired by the K Desktop Environment.
Didactor is an Open Source E-learning environment, written in Java and built on top of MMBase (http://www.mmbase.org). Didactor consists of over 20 didactic components, like e-portfolio, assessment, competence management, group discussion, chat etc.
Free MMORPG Engine. Develop and host graphical browser-based games.
DimensioneX is a free Massive Multiplayer Game Engine. It lets you develop and then run or host browser-based, graphical multiplayer games. The users will play games simply via their browser. DimensioneX runs on any Java-enabled web server (eg. Tomcat)
Geomajas is a web mapping GIS software with full vectorial editing capabilities, and support for custom attribute relation models in the browser. It has built-in support for any type of query, selection, filtering, snapping, printing, ...
A java library too handle different kind of meta data tags from media files. It will also contain utilities to create a database from a given mp3 (or other media) collection, that than can easily be used within mp3 players, catalogs etc.
A thin layer of Java code over Sun's Java code to make life easier for developers. Most of the classes are utility classes for example to support checking of method parameters, String methods, Mathematical methods et cetera.
LokiLib is addon to Jakarta Struts framework.
Get your database online quickly using configuration not code. Use this secure, scalable and proven enterprise technology to publish any relational data, any custom process on the internet. MySQL, Java, XML, XSL. xHTML GUI, beta voiceXML and WML/WAP.
J2EE servlet MVC framework supporting dynamic class loading and template parsing. This framework serves as a building block for creating applications based upon J2EE architecture.