Firebug (software)

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. Firebug was licensed under the BSD license and was initially written in January 2006 by Joe Hewitt, one of the original Firefox creators. In its 0.2.3 release on January 31, 2006, it introduced the F12 shortcut now found in all browsers to open/close the developer tools panel. The Firebug Working Group oversaw the open source development and extension of Firebug. It had two major implementations: an extension for Mozilla Firefox and a bookmarklet implementation called Firebug Lite which can be used with Google Chrome. In addition to debugging web pages, Firebug was used for web security testing and web page performance analysis. Firebug has been deprecated in favor of the integrated developer tools added to Firefox itself, whose functionality has been unified with those of Firebug. As Firefox 57 no longer supports XUL add-ons, Firebug is no longer compatible. Firebug 2.0 introduced many new features to the Firebug extension including JavaScript syntax highlighting, pretty print for minified JavaScript code, and a DOM Event Inspector to handle all event handlers on a web page. Additionally, users can search for page elements using CSS selectors in the search bar.