tmux

tmux enables a number of terminals (or windows) to be accessed and controlled from a single terminal like screen. tmux runs as a server-client system. A server is created automatically when necessary and holds a number of sessions, each of which may have a number of windows linked to it. Any number of clients may connect to a session, or the server may be controlled by issuing commands with tmux. Communication takes place through a socket, by default placed in /tmp. Moreover tmux provides a consistent and well-documented command interface, with the same syntax whether used interactively, as a key binding, or from the shell. It offers a choice of vim or Emacs key layouts.

Only use this tool against systems you own or are explicitly authorized to test — see the disclaimer.