Firebug

==2006-2010==
Firebug is a discontinued free and open-source web browser extension for Mozilla Firefox that facilitated the live debugging, editing, and monitoring of any website's CSS, HTML, DOM, XHR, and JavaScript.
==2010–2017==
In 2017, as Firefox 57 no longer supports XUL add-ons, Firebug is no longer compatible, thus making it discontinued.
Category:Mozilla
Category:Firefox
Category:2009
Category:Defunct