Where have all the XML validators gone?

It seems the XML Validation service is down/unavailable/what-have-you, and many of the other XML validators just don't seem to work.

However, Validome has a pretty good service.

You have to make sure you grab the right language, but, other than that ...

I've got my XML file - http://jamesrskemp.net/vehicle_gas.xml - validating with a DTD, but my attempts at getting a schema to work failed pretty hard ...