Using /etc/xml/catalog with org.apache.xml.resolver
I have just reported the bug in the w3c-dtd-xhtml Ubuntu package that had prevented me from using the Apache XML Catalog resolver to use local XHTML DTDs rather than the on-line ones when using the Saxon XSLT processor.
Hitting the on-line DTDs on every invokation of Saxon unnecessarily burdens the W3C Web site. I had already found guidance on how to use the Apache XML Catalog resolver to avoid that, but it wouldn’t work with the default XML catalog list provided by Ubuntu in /etc/xml/catalog for the XHTML DTDs.