Spinneret is a structured storage engine that can be thought of as an extended tuple storage system. It takes the best aspects of relational, object, and hierarchical databases and throws away the dead weight associated with those technologies. The benefit of Spinneret is that its data model is incredibly flexible, allowing it to expose its underlying data in any number of ways. It operates similar to an object database, but without hard ties to an originating language, and can also behave like a relational database without the burden of complex joins.
Poor Man's Imaging Wrapper a clean and simple API wrapper over JAI, Java2D, ImageIO, and AWT. It supports a set of imaging operations (read, write, scale/resize, crop, grayscale, add transparency, rotate, add border, flip/mirror, add text, overlay, blur, sharpen, etc.) with simple direct calls to the API. If you want to switch from Java2D to JAI, all you need to do is add JAI jars to the classpath. It supports GIF encoding if PJA tools jars are available in the classpath.
Rome is a set of Atom/RSS Java utilities that make it easy to work in Java with most syndication formats. It accepts all current flavors of RSS (0.90, 0.91, 0.92, 0.93, 0.94, 1.0, and 2.0) and Atom 0.3 feeds. Rome includes a set of parsers and generators for the various flavors of feeds, as well as converters to convert from one format to another. The parsers can give you back Java objects that are either specific for the format you want to work with, or a generic normalized SyndFeed object that lets you work on with the data without bothering about the underlying format.
Apache Rivet is a system for creating dynamic Web content via a programming language integrated with Apache Web Server. It is designed to be fast, powerful and extensible, consume few system resources, be easy to learn, and to provide the user with a platform that can also be used for other programming tasks outside the web (GUIs, system administration tasks, text processing, database manipulation, XML, etc.). It is similar to PHP, except that it uses Tcl, and provides both HTML/Tcl pages as well as pure Tcl pages to aid the programmer in separating logic and presentation when necessary.