ViewSourceWith is an excellent tool!
Using a short shell script as "editor", it can be used to easily validate script generated (X)HTML output using the W3C validator.
But unfortunately the DOM Save output does not validate even for valid sources.
It would be a nice feature if this could be changed.
Probably there are only two points in the DOM Save output that prohibit successful validation:
1st: "<!DOCTYPE HTML PUBLIC ..." should be "<!DOCTYPE html PUBLIC ..."
2nd: "<meta ...>" should be "<meta ... />" (same with all self-closing elements like <img .../>, <input ... /> etc.)
Thank you very much!