I\'m writing an XML schema (an XSD) to describe the format our partners should send us data in.
And I\'m having a hard time finding a tool that can validate the XSD sche
If this is a short-term thing, you could use an evaluation copy of a tool like Stylus Studio.
If it's long-term maintenance, you might want to consider purchasing an XML schema editor like Stylus, or Oxygen or Altova.
You didn't specify the source language, but it's only a few lines of code to write a schema validator in Java or .Net.