Firefox

Auto-fill toolbar
To get the IE8 shift-enter style behaviour in Firefox


 * 1) Enter "about:config" in the URL search bar in Firefox
 * 2) In the Firefox config, search for this string "browser.urlbar.autoFill"
 * 3) Set this option to "true"

N.B: This feature just does not work very well

Browser plugins

 * Firebug edit, debug, and monitor CSS, HTML, and JavaScript live in any web page
 * Web Developer various web developer tools
 * LiveHTTPHeaders HTTP headers
 * Screengrab! screen capture tool for Firefox
 * Fireshot FireShot is a extension for Firefox and Internet Explorer that captures, edits, annotates, organizes, exports and prints screenshots of your web pages.
 * Selenium Web application testing system.