OSCache is a high performance J2EE caching solution that can cache portions of JSP pages, entire HTTP responses (including dynamically generated images), and arbitrary Java objects. It can provide your J2EE application with huge performance gains and graceful error tolerance (e.g., in the event of a DB failure, cached content is served).
Batik is a Java-based toolkit for applications that want to use images in the Scalable Vector Graphics (SVG) format for various purposes, such as viewing, generation, or manipulation. It gives developers a set of core modules (parsers, generators, DOM implementation) which can be used together or individually, and be highly extensible. It comes with a full-fledged SVG viewer.
KOJAC is a set of Java classes implementing optical elements and optics laws in order to build and simulate optical systems. It is also aimed at being a demonstrator of optics for educational purposes. Optical systems are composed of objects with defined properties that may be modified by the user through the applet's buttons and scrollbars. Such basic devices are lenses, apertures, interfaces, and may be themselves composite sets of other elements. KOJAC is able to do exact raytracing in 3 dimensions, taking into account the wavelength of the rays, and simulating real materials.
Jacomma is a framework for developing network-aware, mobile, reactive information agents with heterogeneous communication capabilities. It currently uses the ICM agent communication infrastructure. It offers transparent ICM bindings for Java, and includes a lightweight agent execution environment.