Firefox Quantum isn't a rewrite of Gecko. At one point, Servo was going to be a rewrite of Gecko, but that petered out. They pivoted to a strategy where some pa

Firefox Quantum isn't a rewrite of Gecko. At one point, Servo was going to be a rewrite of Gecko, but that petered out. They pivoted to a strategy where some parts of Servo would be integrated into Gecko, and other components of Gecko would be rewritten in Rust. The most significant of these was Stylo, Servo's CSS style (but not rendering) subsystem. However, despite the rebranding, the core of the engine and the overall architecture is still Gecko.