DocBook is a XML-based standard for describing structured documents. The DrJava documentation (this document, as well as user help) is developed using DocBook. The standard reference describing DocBook tags is DocBook: The Definitive Guide. A second book, DocBook XSL: The Complete Guide, is a good additional reference, especially for its coverage of XML-processing tools.

DocBook documents can be styled as a variety of different formats, including HTML and PDF. This translation leverages generic XML-processing tools, where the meaning of DocBook constructs are defined in separate XSL style sheets. The DocBook style sheets are available from the DocBook SourceForge project, and must be installed in order to generate DrJava's documentation. In addition, the current process relies on xsltproc, an XML translator. (There are a few alternative tools available for Java, but all seem to currently struggle with the DocBook style sheets: Xalan, Saxon, and the standard Java APIs. These are invoked from Ant via the core xslt task.)

Note that there are two similar formats for DocBook documents: XML and SGML. In the past, DrJava used commands docbook2html and docbook2pdf, which processed SGML files. These and other SGML-based tools seem to have been abandoned by the DocBook community, in favor of generic XML-processing tools.