Firefox Focus first launched on iOS, where Apple's WebKit is the only web engine permitted. Focus on Android followed a similar approach using Android's WebView so the Focus team could focus ;) on the app's user experience and privacy features instead of the web engine.

However, Focus (on Android) is now moving to "GeckoView", Firefox for Android's Gecko engine repackaged into a WebView-like component. GeckoView will be available for app developers (Mozilla or others) to build new browsers. Watch Mozilla's Hacks blog for news coming soon! :)

Here are instructions for test driving Focus+GeckoView now:

https://github.com/mozilla-mobile/focus-android/wiki/Release...

The Mozilla Hacks blog post about Firefox Focus and GeckoView is now live:

https://hacks.mozilla.org/2018/09/focus-with-geckoview/

> I _am_ curious about the motivation behind Firefox Focus though. I use vanilla Firefox on Android and really enjoy it.. what was the motivation for using a Webkit base for Focus? Seems like the stripped down, privacy focused experience would have worked fine based on Firefox proper?

I'm pretty sure the answer is quite simple, which is that the Gecko embedding story has been diabolical for a long time (i.e., it's hard to put Gecko in a new product), whereas the majority of WebKit ports and Chromium (through its Embedding Framework, or to a somewhat lesser extent its Content API) are designed to be easily embedded in new applications.

AIUI, the fact this led to this ridiculous situation is part of the reason for the renewed interest in embedding Gecko (and the emergence of GeckoView).

Firefox Focus developer here. Recent improvements in Geckoview (the componentized version of Gecko) mean that it will be much easier to integrate into your own browser projects. We have a whole suite of Android components being developed just for building browser-like software.

The work to make GeckoView offer a full set of functionality in Focus should also help other apps.

Also, don't forget that when Focus was released, Firefox on Android was very very slow. Despite myself being a fan of Firefox, I was using Chrome on Android for purely practical reasons. When Focus appeared, I switched to it, and then at some point to Firefox proper when it's performance became acceptable again. I guess for many users Focus (despite not using Gecko) could've paved road to Firefox.