Interestingly, it's not actually a Chromium clone - it's webkit based, but with WebExtension APIs added to give compatibility with (a growing range of) Firefox

Interestingly, it's not actually a Chromium clone - it's webkit based, but with WebExtension APIs added to give compatibility with (a growing range of) Firefox & Chrome web extensions. I am a Firefox user too, but Orion feels to hit an interesting spot on mobile in terms of the benefits of Safari's power optimisations (via using webkit), with extensions and similar.