Cluster ssh for iTerm2
I have used csshX for a while now and I love it, but a couple years ago I made the switch to iTerm as my primary terminal, so I built an equivalent tool for iTerm.
This is iTerm2 2.9+ compatible (the AppleScript API in iTerm changed significantly in 2.9).
The whole tool is just an AppleScript in the shell script isshx, so it can be copied or symlinked anywhere in your path.
isshx only needs a list of servers to ssh to:
isshx SERVER_HOST [SERVER_HOST [SERVER_HOST [...]]]
Once the new terminal window is open you can use iTerm's native support for broadcast to send input to all sessions in the window. By default, this Cmd + Shift + I to enable/disable broadcast.
Take note that when you enable broadcast to a window, it will enable it for all sessions in all subwindows as well as any session in other tabs of that particular window. This is why isshx creates a new window every time.