Provides the following services: implementation of complete UML 1.3 physical metamodel, easy to use interfaces, event notification, undo/redo support, reflective API, XMI loading/saving. [Open Source, LGPL]

A business rule engine class library.

A Java library consisting of a number of iterators, algorithms and functions, loosely inspired by the C++ Standard Template Library. [Open source, LGPL]

A binding for SDL (Simple DirectMedia Layer) written in java. Now you can use SDL and still program with Java. [Open source, LGPL]

A meta architecture for the Java virtual machine.

A general-purpose plug-in framework intended to help building scalable, extendable Java applications with low cost of maintenance. [Open source, LGPL]

Renders Java 1.1 GUIs written in AWT that do not implement custom graphics to a text console. [Open Source]

Class libraries that extend JDK libraries, providing many commonly-used algorithms and data structures. By Recursion Software, Inc. [Commercial]

A Java class library for deduction rules. It provides an infrastructure for defining, managing and querying rule engine bases. [Open source, LGPL]

A class library providing object-oriented representations and algorithms for logic, mathematics and artificial intelligence. It comprises theorem proving, computer algebra, search and planning, as well as learning algorithms.