Q:

How to generate pdf from docbook 5.0

I've written a docbook 5.0 document with the header:
<?xml version="1.0" encoding="UTF-8"?>
<book version="5.0" xmlns="http://docbook.org/ns/docbook"
      xmlns:xlink="http://www.w3.org/1999/xlink"
      xmlns:xi="http://www.w3.org/2001/XInclude"
      xmlns:svg="http://www.w3.org/2000/svg"
      xmlns:m="http://www.w3.org/1998/Math/MathML"
      xmlns:html="http://www.w3.org/1999/xhtml"
      xmlns:db="http://docbook.org/ns/docbook">

and docbook2pdf on Ubuntu 9.10 prints many error messages and doesn't do any pdf document. The  errors are:
openjade:test.xml:2:0:E: prolog can't be omitted unless CONCUR NO and LINK EXPLICIT NO and either IMPLYDEF ELEMENT YES or IMPLYDEF DOCTYPE YES
openjade:test.xml:2:0:E: no document type declaration; will parse without validation
openjade:/usr/share/sgml/docbook/stylesheet/dsssl/modular/print/dbtitle.dsl:18:5:E: flow objects at the root must be all of class scroll or all of class page-sequence or simple-page-sequence
openjade:/usr/share/sgml/docbook/stylesheet/dsssl/modular/print/dbbibl.dsl:704:4:E: flow objects at the root must be all of class scroll or all of class page-sequence or simple-page-sequence

docbook2pdf for document in the docbook 4.5 format with normal header like: 
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">

works quite OK.
Is there any way to generate pdf from docbook 5.0?

A:

I see three options (available in Debian/Ubuntu) to generate pdf from docbook:

jade, which provides the docbook2pdf command the asker used. jade is ancient and works with SGML, which predates XML and does not support Unicode; it also lacks support for docbook 5.
the docbook-xsl stylesheets which go through XSL-FO. docbook-xsl is for docbook 4.5, docbook-xsl-ns is for docbook5. Use fop to go from XSL-FO to PDF. Pipeline: docbook5 —(xsl)—> xml.fo —(fop)—> pdf . Commands involved: xsltproc, fop.
dblatex, which is primarily targeting docbook4.5 but has been updated for some of docbook5.

xmlto can drive the last two, although it currently defaults to docbook-xsl and not docbook-xsl-ns.

A quick Docbook5 user guide
Prerequisites
sudo aptitude install docbook5 docbook-xsl-ns xsltproc fop xmlto libxml2-utils xmlstarlet

Validation
xmlstarlet val --err --xsd /usr/share/xml/docbook/schema/xsd/5.0/docbook.xsd book.xml

PDF output
xsltproc /usr/share/xml/docbook/stylesheet/docbook-xsl-ns/fo/docbook.xsl book.xml > book.fo
fop -fo book.fo -pdf book.pdf

A:

Apart from the header you gave, did you try a smaller example, like this one from the DocBook 5.0: The Definitive Guide ?
<?xml version="1.0" encoding="UTF-8"?>

<book xmlns='http://docbook.org/ns/docbook'>
  <title>An Example Book</title>
  <titleabbrev>Example</titleabbrev>
  <info>
    <legalnotice><para>No notice is required.</para></legalnotice>
    <author><personname>
      <firstname>Norman</firstname><surname>Walsh</surname>
    </personname></author>
  </info>

  <dedication>
  <para>
      This book is dedicated to you.
  </para>
  </dedication>

  <preface>
    <title>Foreword</title>
    <para>
        Some content is always required.
    </para>
  </preface>

  <chapter>
    <title>A Chapter</title>
    <para>
        Content is required in chapters too.
    </para>
  </chapter>

  <appendix>
    <title>Optional Appendix</title>
    <para>
        Appendixes are optional.
    </para>
  </appendix>
</book>

Just rendered it to a PDF through one of my Maven environments. Can you give a small example (or a few separated onces) containing some content, which makes the use of all the additional name spaces necessary.
In case the above example does not work, and you are interested in how I have setup my environment read Making DocBook content available in a Maven project site. Just replace the example with the above DocBook 5.0 example. Only the docbkx-maven-plugin is of interest, in relation to this question. (PS: Some basic knowledge of Java and Maven2 is required for this.)

