Rated 5 out of 5 stars

This is a great tool. I've been using it for quite a while. The color highlighting makes it easy to check a page quickly.

There is a 0.6.4 version (for testing) that was uploaded to addons.mozilla.org on June 30th, that works well with Firefox 3.5.*.

https://addons.mozilla.org/en-US/firefox/addons/versions/532#version-0.6.4

This review is for a previous version of the add-on (0.6.4).