where to find xsl stylesheets with namespace?

Where is the official release for the docbook stylesheets that handle namespaces? The link 

http://docbook.sourceforge.net/

Only gives me links to the non namespace stylesheets. The only way I can find stylesheets with namespaces is to click on the "bleeding edge" link, but I thought there were stable, common releases that were not bleeding edge. 

When I do try to process a stylesheet with:

xsltproc http://50.56.245.89/xsl-ns/fo/docbook.xsl my_doc_docbook.xml

I get errors that no match is found for the mathml elements:

Element math in namespace 'http://www.w3.org/1998/Math/MathML' encountered in d:equation, but no template matches. ...

Thanks

Paul