XWidglets is a complete rich Java Swing tool for designing, creating, and using XML-based GUIs. It provides a lightweight XML client, clear separation between view, data, and process, MVC I and II support, event management, a consistent look and feel across platforms, a rich set of GUI components, and n-tier architecture integration.
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.
ServingXML is a markup language for expressing XML pipelines and an extensible Java framework for defining the elements of the language. It defines a vocabulary for expressing flat-XML, XML-flat, flat-flat, and XML-XML transformations in pipelines. The accompanying console app supports reading content as XML files, flat files, SQL queries, or SAX events, and writing it as XML, HTML, PDF, or mail attachments. This software is especially suited for converting flat file or database records to XML, with its support for namespaces, variant record types, multi-valued fields, segments and repeating groups, hierarchical grouping of records, and row-by-row validation with XML Schema. There is also an API for embedding the software in a Java application.
While the author of BSAX-J has not yet come to a final conclusion about the need for a binary XML format, BSAX is his idea of one possible encoding that leverages other XML prior art (SAX events and UTF-8, in particular). It is complete in that it can be used to perform round-trip conversions from textual XML to SAX events to BSAX binary streams, and back to SAX events and textual XML. The test code in the distribution does exactly that for a simple example XML file, and measures the difference in file size (the file is slightly smaller for the BSAX encoding of the sample file) and the difference in read time (the read time is significantly faster for the sample file).
Apache XML Graphics Commons is a library that consists of several reusable components used by Apache Batik and Apache FOP. Many of these components can easily be used separately outside the domains of SVG and XSL-FO. You will find components such as a PDF library, an RTF library, Graphics2D implementations that let you generate PDF and PostScript files, and much more.