point 2 about atom:

Well, writing a text editor is far more complicated than it seems at first place.In order to support big files (50mb logs for instance), you need to make all your code rely on complex memory management, streaming and caching. Maybe js is not the right tool for the job in order to implement these features. I always thought that atom should be build in Qt with an api that can interact with JS,a bit like Adobe products for instance. That way you still allow JS plugins, just like Photoshop while getting a max of perfs thanks to C++.