I&#x27;m all for writing new apps in HTML, I think Atom and VSCode are awesome, but I&#x27;m not for rewriting huge legacy apps to be HTML apps for no good reason. The reasons given, that XUL requires maintenance that Mozilla engineers don&#x27;t enjoy doing, is a joke considering the amount of effort to maintain XUL is less than 1% of the amount of effort to move Firefox to HTML.<p>No one has listed the ten awesome features that we&#x27;re going to get from HTML Firefox (cause there ain&#x27;t many) or the 1,000 features (tons of little details) that will be lost. If users listed their 10 biggest problems with Firefox I doubt any of them would be solved by moving to HTML.<p>Imagine if instead of writing VSCode from scratch and releasing it alongside Visual Studio Microsoft had rewritten the Visual Studio UI in HTML, abandoned all the nonessential features, and abandoned the old native Visual Studio.<p>One might say that Mozilla will wait to release the new Firefox till it has all the old features of the old Firefox, but that&#x27;s not been my experience with how teams work. They&#x27;ll get frustrated with the rewrite and want to get it out the door. &quot;We can add those features later&quot; they will say, and then they&#x27;ll never get added.