I'd guess that IE is too gargantuan a project with too many people involved and too much history (read: compatibility baggage) to be able to say, "welp, let's j

I'd guess that IE is too gargantuan a project with too many people involved and too much history (read: compatibility baggage) to be able to say, "welp, let's just fork it." Doubtless internal politics and MS's own corporate shortsightedness also have a big say in it. But that's just my guess.