Mac – Emacs: displaying list of subroutines/functions/classes in a source file

Your init file contains personal EmacsLisp code that you want to execute when you start Emacs.

• For GnuEmacs, it is ~/.emacs or _emacs or ~/.emacs.d/init.el.
• For XEmacs, it is ~/.xemacs or ~/.xemacs/init.el.

You can open the same buffer in more than one window (which can be spread amongst different frames), but it's not very convenient. Each window has its own point, but they all share the mark, the file mode, the narrowing and other characteristics, because apart from the point pretty much all characteristics are tied with the buffer. Also, if you happen to visit another buffer in one window, you'll lose your place in the file.

You can make an indirect buffer which has its own point, mark, modes and so on, but the same content as the original buffer (and saving either buffer writes to the same file). To create a second buffer that is a clone of the current buffer, run M-x clone-indirect-buffer RET. To open that second buffer in a different window, you can type C-x 4 c.