&gt; <i>the lack of html rel import in Firefox. Any word if that&#x27;s ever going to change?</i><p>Right now we have no intention of shipping HTML Imports; it&#x27;s easy to polyfill, and we suspect that implementing ES2015 Modules and the module loader spec will change how we look at the problem of reusable components. To that end, support for a restricted subset of &lt;script type=&quot;module&quot;&gt; should land in Firefox Nightly builds tomorrow (<a href="https:&#x2F;&#x2F;bugzil.la&#x2F;1240072" rel="nofollow">https:&#x2F;&#x2F;bugzil.la&#x2F;1240072</a>), so we&#x27;re making significant progress on that front.