XVisitor is a plugin for the xjc code generator to enrich the JAXB model generated from an XML schema so that users can work with the Visitor pattern on this model.
Working with large XML documents is a significant part of my job at the moment, and I've found that both JAXB and the Visitor pattern provide useful type-safe abstractions compared to working with DOM and XPath only. This was the motivation for creating XVisitor as an open source project with an Apache License.
XVisitor is hosted by the OPS4J community, which offers first class infrastructure for Apache-licensed Java projects, including Confluence, GitHub, Hudson, JIRA and Maven Central releases.
For more details about XVisitor, check out the wiki.