Er, but why not? Mozilla is a group founded long ago to build a web browser, and up to this day still centered around their web browser. I would expect their code to be quite performant... If I've got this right, UP is using "oxide" for their web engine, and oxide is based on chromium. Therefore, UP is using Google's engine for its web layout; which, again, should provide a superior browsing experience. And, again, this is also what Qt themselves have recently done -- pretty much given up on their existing webkit engine, and gone with Chromium. If/when Jolla migrates to the more recent versions of Qt, their browser should hopefully better match Ubuntu Phone and other chromium-based systems...