Emacs. You're looking for follow-mode: http://www.gnu.org/software/emacs/manual/html%5Fnode/emacs/Follow-Mode.html http://www.gnu.org/software/emacs/manual/htm

Emacs. You're looking for follow-mode: http://www.gnu.org/software/emacs/manual/html%5Fnode/emacs/Follow-Mode.html http://www.gnu.org/software/emacs/manual/html%5Fnode/emacs/F... The ability to edit the same file (or, in emacs terms, "buffer") in two or more windows is a killer feature.