On the other hand, XSL-FO does go beyond CSS in some respects that
are important for high-quality printing. For example, XSL-FO offers
multiple column layouts; CSS doesn't. XSL-FO can
condition formatting on what's actually in the
document; CSS can't. XSL-FO allows you to place
footnotes, running headers, and other information in the margins of a
page; CSS doesn't. XSL-FO lets you insert page
numbers and automatically cross-reference particular pages by number;
CSS doesn't. And for printing, the requirement to
render into PDF is much less limiting and annoying since the ultimate
delivery mechanism is paper anyway. CSS Level 3 will add some of
these features, but it will still focus on ease-of-use and web-based
presentation rather than high-quality printing. Once the software is
more reliable and complete, XSL-FO should be the clear choice for
professionally typeset books, magazines, newspapers, and other
printed matter that's rendered from XML documents.
It should be very competitive with other solutions like Quark XPress,
TEX, troff, and FrameMaker. CSS does not even attempt to compete in
this area.