The following text can be found on this blog post concerning depricating XUL: The Future of Developin Firefox Add-Ons
We will also continue supporting SDK add-ons as long as they don’t use require(‘chrome’) or some of the low-level APIs that provide access to XUL elements.
However, I just installed the Firefox Nightly build and my test add-on seems to be working fine, although it uses require(‘chrome’).
Relevant code from the add-on:
var { Cc, Ci } = require("chrome");
var SearchService = Cc["@mozilla.org/browser/search-service;1"].getService(Ci.nsIBrowserSearchService);
SearchService.addEngineWithDetails('mysearch', 'icon', 'mysearchalias', 'my search description', 'get', 'http://stackoverflow.com/search?q={searchTerms}');
SearchService.currentEngine = SearchService.getEngineByName('mysearch');
Am I misunderstanding something? Will the support for require(‘chrome’) be dropped at a later time?