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

A Java framework for creating online multiplayer games. [Open source, GPL]

General purpose Java tools libraries: Lib (Objects, Strings, Files, FileFormat, Web, Tools, ZipInput); run - a Java application that runs code from a URL; jsp - Universal JSP turns JSP language into Macro; Practical XML - a very simple XML library.

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 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.

This package provides standardized, efficient versions of utility classes commonly encountered in concurrent Java programming. It mainly consists of implementations of a few interfaces. [Open Source, Public Domain]

A collections framework for primitive Java types. The framework supports all primitive types and includes bridges to the standard Java Collections Framework. [Open source, LGPL]

Java utility libraries for text, IO, XML, database. Online javadocs. [Open source]

A job scheduling system that can be integrated with, or used alongside any Java application. Quartz can be used to create simple or complex schedules for executing jobs, whose tasks are defined as standard Java components or EJBs. [Open source, Apache...

Offers libraries for the Java platform, such as dated collections, print preview, report visualization, and an OODB. [Commercial]