Cypress is an open-source Cascading Style Sheet (CSS) parser that lets you add well-documented, standardized name/value pairs (a.k.a. CSS style properties) to your own XML markup languages. It supports inline styles so you can add style properties to individual XML tags using the style attribute or external style sheets so that you can store style rules for reuse in separate, XML-free text documents. Cypress supports three forms of selectors to match your XML tags and style rules, that is, element selectors, class selectors, and id selectors.
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.
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.
SitemapGen4j is a Java library to generate XML sitemaps. It supports gzipped output, sitemap validation, and sitemap index generation. It can also generate Google-specific sitemaps, such as Mobile sitemaps, Geo sitemaps, Code Search sitemaps, Google News sitemaps, and Video sitemaps.