
this site provides DSSSL technique and so on.
DSSSL is Document Style Semantics and Specification Language. you can format SGML/XML by using DSSSL stylesheet.
it has similar relationship in contrast to HTML and CSS.
If you want to try DSSSL scripting, you can use following processor.
OpenJade is freely used DSSSL processor. it is originally implemented by James Clark's.
see OpenJade site in details.