User:DGolden:Follow

Emacs allows multiple "windows" (panes) in its "frames" (windows), allowing different buffers (files/pages, kinda) to be viewed in each. That is a feature request in firefox already, actually.

But in addition, there is, at least in GNU Emacs, a special hack called "follow mode". That allows one buffer to be displayed in two or more panes, with the areas of the buffer in each pane leading on from eachother, and the scrolling synchronised to keep it that way (in the emacs implementation, each pane retains a scrollbar, but each scrollbar in effect scrolls both panes in lockstep)

That is to say, it's a UI-level multicolumn mode. Given people have very large, high-res monitors these days, and web designers always seem to make those annoyng narrow fixed-width pages, a UI-level multicolumn mode for firefox would be handy I think.

Given the complexities of wrapping, requiring all involved panes to be the same width would be okay for a version 1, though it's not actually a constraint of the (text-oriented, of course) emacs follow mode - an obvious later enhancement would be to allow the panes to be different widths.

Screenshot of emacs using follow mode: