Jukebox is a collection of reusable components that allow you to create a flexible server-side and middleware framework. It features semaphores and services (not quite your usual set), a Finite State Machine implementation based on Generics, a Datastream framework (data producers, consumers and loggers), and a JDK 1.6 compliant JMX framework based on Annotations.
Hibersap is a small framework that offers an abstraction layer on top of the SAP Java Connector (JCo). It maps Java classes to SAP function modules using Java Annotations and reduces the technical code to call a function in a SAP back-end system. Hibersap’s API is very similar to Hibernate, thus offering a familiar programming interface to developers of enterprise applications.
Contracts for Java (Cofoja) adds contract programming support to Java through simple yet powerful annotations: @Requires, @Ensures, @Invariant, and @ThrowEnsures. Contracts are inherited from interfaces and superclasses and can be enabled selectively during development then disabled for release.