Yeah, I actually looked at atom sometime back. They have a problem with long lines because their regex engine runs in O(n^2). I suggested that they switch to a regex engine that runs in O(n). https://github.com/atom/atom/issues/979#issuecomment-7770371...

I don't know what happened after that. Maybe they will act on this. The only problem with the O(n) engine was that a lot of TextMate grammars for languages wouldn't work with atom but that was easily resolvable by writing them anew.