The switch to Geckoview is for Firefox Focus, which previously used Blink (the Chrome rendering engine). Standard Firefox for Android has used Gecko from the s

The switch to Geckoview is for Firefox Focus, which previously used Blink (the Chrome rendering engine). Standard Firefox for Android has used Gecko from the start. It is gradually being upgraded using the Quantum improvements, but the rate of change seems slow. I thought that the emphasis on multi-threaded processing in Quantum would be particularly useful for mobile, because the single threaded processing capability of mobile (and particularly non-Apple mobile chips) is very limited, but there don't seem to have been massive improvements. I think it’s a shame they relegated Servo to a research project, integrating Servo into Gecko has been long-winded, and the most important target of porting a parallel/multi-threaded layout engine isn’t even being discussed. Frankly, given their $500m budget, their core mission of browser development, and the massive importance of mobile, they probably should have pursued both Gecko and Servo at the same time. Even if Servo only supported flexbox layouts it could be very useful as a wrapper while wider compability was being pursued. The emphasis now is on WebVR, which seems not very relevant to the mass market.