The thing that gets me about Mozilla is they were doing thing with xulrunner years ago that WebKit is being used for now with electron apps. But Mozilla didn't develop it. There were crossplatform apps being built with gecko.
I recall that Xulrunner, similar to the Firefox UI back in the day, hesitates just a little bit before responding to events. Perhaps xulrunner was too early in relations to computer performance back in the day, or they simply made a technical error when designing Gecko.
