http://livehttpheaders.mozdev.org/suggestions.html#c440 Johannes la Poutré has made a few changes to allow livehttpheaders to be installed in Firefox 3 beta: http://squio.nl/blog/2008/01/22/livehttpheaders-for-firefox-30-beta/ Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9b3) Gecko/2008020514 Firefox/3.0b3