Nice but limited validator for the Web developer Rated 4 out of 5 stars
It's a useful extension but it lacks XHTML strict validation for example, instead you have to manually use the W3C online validation tool. But the extension is great to quickly check for HTML/CSS websites or accessibility issues.This review is for a previous version of the add-on (0.8.3.9).
Top add-on Rated 5 out of 5 stars
Such a great add-on, right up there with Firebug and Web developer extension as essential add-ons. The new OpenSP validator as used by the w3c validator is a fantastic new addition.
Certainly alot easier to use than installing the w3c validator on a windows dev machine. Keep up the great work.