Just thought I'd mention that jQuery can be used with Prism. All you need to do is redeclare "document" as a local variable (which points to the browser) and you can then put jQuery inside the webapp.js file. :)
e.g. function doStuff(document){ //put jQuery packed here $('body').prepend('<div>jQuery Rocks!</div>'); } function startup() { var appcontent = host.getBrowser(); if(appcontent){ appcontent.addEventListener("DOMContentLoaded", function(aEvent) { doStuff(aEvent.originalTarget); }, true); } }