single-source publishing—one source document, many target output formats
print output (PostScript, PDF, RTF)
Web output (HTML/XHTML, single page, chunked output)
help systems (HTMLHelp, info, man, JavaHelp, Eclipse help)
other formats (WordML, LaTeX, ConTeXt)
transformation from DocBook XML into various output formats is done by XSLT
DocBook XSL stylesheets are free and open-source
modular documents—content reuse
conditional documents
authors no longer have to worry about presentation