Emacs: Make Buffer Flow Side-by-Side
you can set emacs to display a file side-by-side, with left bottom continue to right top. When cursor moves to the bottom of left pane, it'll appear on the right top.
This is most useful if you have wide screen.
You can use mouse to scroll. It'll scroll both panes.
follow-mode again to toggle off.
2011, Thanks to Zhang Tianjin for mentioning this tip.