Broadcast in iTerm
iTerm for Mac has a broadcast feature that allows for input to be broadcast to all panes or tabs. This feature can be enabled through the
Shell > Broadcast Input menu in the OS X menu bar. I found the keyboard shortcut
Alt + Cmd + I to be particularly useful. It toggles broadcasting to all panes on and off. The iTerm 2 Beta 3 release also allows for the silencing of the pop-up alert that appears every time the broadcast feature is enabled (warning that input will be broadcast to all panes).