Came here to say this. If it's text, Emacs can handle it. Oh, also, if you want your ASCII diagrams to render into pretty pictures, I found org-mode + ditaa to

Came here to say this. If it's text, Emacs can handle it. Oh, also, if you want your ASCII diagrams to render into pretty pictures, I found org-mode + ditaa to work quite nicely: https://www.orgmode.org/worg/org-contrib/babel/languages/ob-doc-ditaa.html https://www.orgmode.org/worg/org-contrib/babel/languages/ob-...