Servo was a test bed, a place to experiment with new technologies on a minimalist browser. The successful underlying technology was/is being moved into Firefox

Servo was a test bed, a place to experiment with new technologies on a minimalist browser. The successful underlying technology was/is being moved into Firefox (desktop and mobile). There's also a new (I think?) mobile browser in progress. I'm not sure how it fits into the larger picture and information is a bit scarce, they just started releasing beta builds.