Browser Extension to full-text search your browsing history & bookmarks.

The easiest way to measure your performance budget.

Automated tool to find Accessibility defects on your web site by using the aXe Chrome extension. Drop the aXe on your accessibility defects! We believe that automated testing has an important role to play in achieving digital equality and that in order to do that, it must achieve mainstream adoption by professional web developers. That means that the tests must inspire trust, must be fast, must work everywhere and must be available everywhere.

Accessibility audit and element properties.

This extension will add an Accessibility audit, and an Accessibility sidebar pane in the Elements tab, to your Chrome Developer Tools.

Chrome extension for detecting and simulating frontend Single Points Of Failure. Detects likely third-party single points of failure as you browse and allows you to Simulate 3rd party resources being unavailable.
Also, here: https://chrome.google.com/webstore/detail/spof-o-matic/plikhggfbplemddobondkeogomgoodeg

Measure between the following elements: images, input-fields, buttons, videos, gifs, text, icons. You can measure everything you see in the browser.

Zephir, an open source, high-level/domain specific language designed to ease the creation and maintainability of extensions for PHP with a focus on type and memory safety.

A Screen Reading Extension for Firefox

FirePHP enables you to log to your Firebug Console using a simple PHP method call.

All data is sent via response headers and will not interfere with the content on your page.

FirePHP is ideally suited for AJAX development where clean JSON and XML responses are required.

The Web Developer extension adds various web developer tools to a browser. The extension is available for Chrome, Firefox and Opera, and will run on any platform that these browsers support including Windows, OS X and Linux.

Greasemonkey is a Firefox extension that allows you to customize the way webpages look and function.