As part of my teaching web development in our Computer Science program, I use my own course management system that allows student exercise uploads and display of their solutions both in the browser and in syntax highlighted fashion. I can have the program automatically fed into your validator which shows the full report. However, it would be really nice if I could just fetch back a list of errors which I could display in my system beside their solution.
Do you have or are you interested in providing a web service where a page could be passed in as a parameter and a compact error list retrieved as output? The compact list would not be a verbose as the full report but list only the error message, a line number, and a highlighted part of their source. Perhaps the output would be an HTML table?
Just a thought… Thanks for your service; it is great.