I've made some significant changes to the schema, including a tentative XML results schema. I've also added an XML Schema Definition file (schema.xsd) that appears to conform to what we've discussed so far. Please take a look, especially at the results files (contained under /results) and let me know your thoughts and ideas.
I've also included a link to the most recent version of my validator tool, which uses the schema to perform validation.
Note: Windows and the .NET Framework 2.0+ are required to use the tool.
Of special note are options:
/t (performs a self-test on all rules)
/s (Validates the icalvalidSchema against schema.xsd and also ensures all language files are valid)
Please let me know your thoughts.