xml validation, on osx

In OSx, you can rely on the libxml package, which includes xmllint. You will call this on a command line, it's fast and reliable.

A couple of example:

To validate a xml file:

xmllint --noout yourxmlfile.xml

To validate a xml file against a schema:

xmllint --noout --schema yourxsdfile.xsd yourxmlfile.xml