Alternatives to DOM for writing XML

Hi all,
  We are trying to solve the problem of writing large XML documents (so
large that we can't use our DOM parser because of memory constraints)
and are wondering how other people have handled the problem. I know that
although "SAXWriter" isn't formally a part of the the SAX API there are
some libraries that include one, but the parser we use does not. Adding
to the challenge is the fact that our application is C/C++, so we can't
easily use Java support. Any suggestions? Thanks.
--Wayne Henshaw
--Progress Software