They want to kill XUL for Firefox so they can be all fancy HTML. So they have to kill Thunderbird, a XUL app.<p>In a few years the all new HTML Firefox will come out. My bet is that it will suck. It will lack a TON of features that the existing Firefox has, but hey, it&#x27;s all HTML! And you won&#x27;t be able to stick on the old one, because within a week or two some critical security flaw will be discovered and eventually (like six weeks later) they&#x27;ll stop supporting those for old Firefox.<p>Initially the HTML Firefox will suck. When you take an app that&#x27;s been worked on for 15 or so years and then replace it&#x27;s UI you&#x27;re going to lose a TON of features. They&#x27;ll slowly reintroduce some of the most popular features (hamburger menu will be priority #1!) but there will be a TON that they will not reintroduce. Why? Because when they were first introduced a decade ago it was a cool idea someone had, and no one knew how popular it would be, so heck, why not implement it. But now they know that only 10 million or even 1 million people use that feature, and they&#x27;re only interested in 100 million user features! If Google Chrome doesn&#x27;t have it, it must not be important!<p>As much as people complain about XUL not looking native, wait for HTML Firefox, it will take them forever to get where XUL was years ago.<p>They can&#x27;t just kill XUL for Firefox though, they have to burn down the XUL ecosystem first so they&#x27;re just releasing a new Firefox, nothing to see here.<p>1. They try to kill xulrunner as a project separate from Firefox. They try to move everyone to firefox -app.<p>2. They stop releasing binaries for xulrunner.<p>3. They deprecate XUL extensions.<p>4. They distance themselves from Thunderbird. They say it&#x27;s better for Thunderbird. Yeah right! Thunderbird is built on XUL, it&#x27;s not going to be rewritten in HTML any time soon, definitely not by volunteers. It&#x27;s not going to be able to maintain XUL either, and when Mozilla stops supporting XUL for Firefox a few years after deprecating XUL extensions then Thunderbird will be screwed, but hey, it&#x27;s not our project! We abandoned it years ago!<p>So when the crappy HTML Firefox shows up, with way less features than the Firefox of today, remember that this (Thunderbird) was one of the things given up to have it.<p>But hey, donate to Mozilla! $5, $15, $25, anything helps. Because we already make hundreds of millions of dollars and we do whatever is shiny and new, screw the &quot;community&quot; of existing stuff. We&#x27;re fighting for an open web! (where you can use Gmail for email)