I generally use tmux with 3-4 panes open. One of these panes is rarely used, so I'd be happy to hide it away somewhere. I suppose I could do this in a new window, but I'd rather hide it "behind" an existing pane.

For example, I'd like to keep `rails server` running in the background because I rarely need to refer to it, so `guard` occupies that pane instead. When I need to look at the `rails server` output, I'll switch to the `guard` pane and then "tab" over to the `rails server`.

At least, that's the ideal situation, but I can't figure out how to achieve it.