As much as Mozilla would have liked Edge to replace EdgeHTML with its rendering engine, the odds on that happening would have been a lot higher if Mozilla was a

As much as Mozilla would have liked Edge to replace EdgeHTML with its rendering engine, the odds on that happening would have been a lot higher if Mozilla was at a different point in its engineering cycle: it's in the middle of an ambitious rewrite of its own rendering engine, in a new language... With Servo only just in developer preview, it's not going to be fit for Microsoft's enterprise customer needs for another couple of years, and taking a dependency on Rust would have been hard for Microsoft as it has its own languages that serve much the same purpose. Choosing a mature browser platform written on C and C++ makes a lot of sense when thought of in those terms.