[yjftsjthsd-h]

I dunno about standard, but it's been done a bunch.

* As sibling notes, there's ansible (or chef/puppet/salt/...)

* The traditional solution was https://github.com/duncs/clusterssh which opens an xterm to each target plus a window that you type into to mirror input to all of them

* I do the same-ish in tmux with

  bind-key a set-window-option synchronize-panes

and I expect screen and such have equivalent features

* Likewise, there are terminal emulators that let you do splits and then select a menu option to mirror input to all of them