I\'ve written a docbook 5.0 document with the header:
You can use Publican to publish your DocBook XML in PDF, html, and html-single formats. Publican is used by Red Hat as part of its internal documentation toolchain, and is an open source application hosted by the Fedora project. The tool uses "brands" to achieve a modularity in applying styles to the content being published. This preset manner simusing a wide variety of CMS or documentation tools.
A good example of the tool in action is the JBoss Press Gang documentation, which is itself a great resource the gives documentation community guidance on the use of DocBook XML in JBoss documentation. The html and PDF versions were generated with Publican.