Not that this'll be helpful to you, but I *may* use it soon. I just
bought Core PHP Programming, and I also just discovered (elsewhere)
that PHP is beginning to support XML with an embedded interface to
James Clark's non-validating parser "Expat" (see
http://www.php.net/manual/ref.xml.php3). That could prove very
interesting to a number of us forkers.
An alternative people have been mentioning to me for a couple of years
now is http://www.metahtml.org/, which doesn't seem to have any XML
support yet.
What do you get? An existing base of server-parsed things to do within
HTML and a convenient framework within to add new APIs to external,
low-level libraries.
Since browsers may not be supporting XML uniformly for years, isn't it
going to be server-side XML that makes the biggest difference at
first? I'd be interested in news about other open source, server-side
XML tools if people have them in their bookmarks.