If you're using emacs in a native window (not curses/terminal), various modes render e.g. section headings, emphasis, etc right in the buffer you're editing, no

If you're using emacs in a native window (not curses/terminal), various modes render e.g. section headings, emphasis, etc right in the buffer you're editing, no need for a preview window. It's not exactly the markdown / wiki output (because you still see e.g. the `+++` at the beginning of header lines) but you can at least see when you've messed up the markdown (because it doesn't render correctly). It's a bit like syntax highlighting now that I think of it. See the screenshot on e.g. http://www.neilvandyke.org/erin-twiki-emacs/ http://www.neilvandyke.org/erin-twiki-emacs/ for what I'm talking about.