I use Atom not only for coding but also for manuscripts editing. It actually makes a ton of sense to me as I write my manuscripts in Markdown and Atom is provided with many powerful features (specific packages, shortcuts, etc.) that once combined make my writing very efficient (I like to think so). Recently, Timothée Poisot shared a very cool setup:

I also enjoy autocomplete-bibtex and document-outline but I often get quite distracted by the preview and prefer working with a very minimalist environment, which is why I like the zen package so much!