Launch4j is a cross-platform tool for wrapping Java applications distributed as jars in Windows native executables. The executable can be configured to search for a certain JRE version or use a bundled one, and it's possible to set runtime options, like the initial/max heap size. The wrapper also provides better user experience through an application icon, a native pre-JRE splash screen, and a Java download page in case the appropriate JRE cannot be found. The increase in size of the application is small.
MUSCLE (Multi User Server Client Linking Environment) is an N-way messaging server and networking API. It includes client-side networking APIs for various languages, including C, C++, C#, Delphi, Java, and Python. MUSCLE lets programs communicate over a network via streams of serialized Message objects. The included server program ("muscled") lets its clients message each other and store information in its server-side hierarchical database. The database supports flexible queries via hierarchical wildcarding, and "live" updates via a subscription mechanism.
Jodd is a Java utility library and set of frameworks. Jodd tools enrich the JDK with many powerful and feature rich utilities. It helps with everyday tasks, and makes code more robust and reliable. Jodd frameworks is set of lightweight application frameworks, compact yet powerful. Designed following the CoC, DRY, and SCS principles, it makes development simple, but not simpler; you get 90% of the features with 10% of the usual effort.
OPA is a Java GUI application framework that provides services common to mst GUI domains such as window, user option, resource, help, action, module, log, and directory management. It is based on a module architecture where modules (JAR files) are added at start-up and make use of the services provided.