jPersist is an extremely powerful object-relational database persistence API that manages to avoid the need for configuration and annotation; mapping is automatic (A-O/RM). It uses JDBC, and can work with any relational database and any type of connection resource. It uses information obtained from the database to handle mapping between the database and Java objects, so mapping configuration is not needed, and annotation is not needed. In fact, there is no configuration needed at all.
jQKat is a simple Java class to obtain data from the free RadioShack CueCat(tm) bar code reader in standard format. It returns a String of the actual bar code data. It has been tested against many books and routine household products. It can also decode strings that have already been received from the CueCat reader.
jRapidRPC is a Java RPC library that allows you to create client-server applications that talk in objects. It is small, fast, and extensible. Its smallness helps you learn how to use the library quickly. jRapidRPC is fast due to its compact size and lack of complexity. Also, it uses the ProtoStuff serializer by default. jRapidRPC's extensibility allows you to can write a new client-server or a new serializer.
jRate is an extension of the GNU GCJ compiler front-end and runtime system that adds support for most of the features required by the Real-Time Specification for Java (RTSJ), including threading constructs with real-time constraints, asynchronous event handling, and memory regions. It was initially developed at Washington University in St. Louis and is released under a license similar to GCC's GPL license that allows non-GPLed programs to be compiled and linked.
jSettings is a framework for Java developers, allowing them to import configuration and settings from external files, manage the imports (access, add, delete, and modify the settings), and export the changes back to files. Features include support for settings validation using regular expressions, system-wide and user-specific management, the ability to undo changes, flushing to files, and more.