If you read the manpage, you can see that there are three back ends.
The default is passivetex (which has not been maintained for years). Some people think that pdfxmltex (part of texlive) will suffice (configure checks for xmltex and pdfxmltex), but like every other package which tries to use that, the current version is too new.
Both dblatex and fop work, so at runtime you can pass
if you have them installed, e.g. to create a PDF from xmlto.pdf.
dblatex correctly handles the second author's name, fop produces 'r#' instead of r-caron.
NB installing dblatex needs texlive.