The current version of RXP supports XML 1.1, Namespaces 1.1, xml:id,
and XML Catalogs. To use an XML Catalog, set the environment variable
XML_CATALOG_FILES to a space-separated list of catalog files.

RXP was written by Richard Tobin at the Language Technology Group,
Human Communication Research Centre, University of Edinburgh.

A simple application (called rxp) is provided. It parses and writes XML
data, optionally expanding entities, defaulting attributes, and
translating to a different output encoding.

Bug reports should be sent to richard@cogsci.ed.ac.uk.