XSLT is a W3 specification that allows general transformations from XML into practically any other format (mainly XML, but you can also create any text).
And the best of all: All these export styles are not hard-coded in C++, but they are pure xml files that can be edited by anyone (okay, not really anyone, you need to know XSLT). Due to KDE's nice standard dirs approach, there are some system-wide style sheets, but each user can also add her/his own style sheets in one's home directory.
Unfortunatly, I'm not much of a graphics or web designer, so the output of the transforms is currently really ugly (and not completely implemented in XSLT, either). But at least the technology is there, now only the style sheets have to be implemented and polished.