I think we should also consider using architectural
forms for specifying presentation for XML documents.
A simple "XML online display architecture" -- most
likely based on HTML -- would be sufficient for many
user applications, and would probably be significantly
easier than either DSSSL or CSS.

It would be easier for implementors: the display engine
would only need to deal with a single architecture (no
harder than writing an HTML browser), and an architecture
engine only adds a little more work.  (The architecture
engine doesn't even have to be based on the AFDR; indeed,
in the absense of a DTD the AFDR is probably not workable.)

It would be easier for users: mapping DTDs to an architecture
is much simpler than writing a DSSSL stylesheet, and possibly
simpler than CSS too.

It would be more work for us though: we'd need to define the
architecture, and possibly a new mechanism for architectural
transformation.  (Then again maybe not; the former could be
based on HTML, and the latter could be a subset of the AFDR.
This might not take any more work than defining a DSSSL application
profile or modifying CSS to support arbitrary document types

--Joe English