Source and all schema has to be local files
The source XML file as well as all parts of the schema (including all xsd:include) have to be available as local files. Entering an URL will result in an I/O error. When entering an invalid local file (e.g. a directory) - but even when everything is setup correctly - parsing will take age without any CPU activity. I guess the program still tries to open a network connection and fails eventually. I do consider the possibility to check one URL with a XML document against another URL with a XSD as a rather important feature.
The program will validate correctly, when all files are local. Id also like the option to validate a bunch of files per wildcard. All these seems like rather minor work compared to the available functionality but impede usability significantly. I will definitely improve my rating when / if these issues are resolved (especially the I/O errors with URLs).
Available Nick5 about XML Nanny, v1.0.3