So, das sollte auch unter Linux funktionieren:
Components.utils.import("resource://gre/modules/Microformats.js"); jetpack.statusBar.append({ html: '<img src="http://microformats.org/favicon.ico"> hCards: <span id="hcard-count">0</span>', onReady: function(jetpackWidget) { function counthCard(){ //load HTML var doc = jetpack.tabs.focused.contentDocument; // count microformats var uFcount = Microformats.count('hCard', doc); if (uFcount > 0) { $(jetpackWidget).find('#hcard-count').html(uFcount); } } jetpack.tabs.onFocus(counthCard); } });