The Xerces-Based XML Parser is invoked in a manner similar to OmniMark's built-in SGML and XML parsers, differing only in specifying "markup-parse xerces-xml" instead of "xml-parse document" or something like it:
include "omxerces.xin" process do markup-parse xerces-xml scan file "my.xml" output "%c" done
omxerces, you must download the Xerces 2.1 binaries from the Apache website and install on your system. If you are using HP-UX, you must go to the developers resources page of the OmniMark website and download the binaries from there. In either case, follow the installation instructions on the Apache website.