A terminal multiplexer can be thought of as a text version of graphical window managers, or as a way of putting attach virtual terminals to any login session. It is a wrapper that allows multiple text programs to run at the same time, and provides features that allow the user to use the programs within a single interface productively. ; Persistence: Similar to VNC, many terminal multiplexers allow the user to start applications from one computer, and then reconnect from a different computer and continue using the same application without having to restart it. This makes accessing the same session between different locations like work and home simple. These multiplexers generally provide terminal-agnostic functionality so that users can disconnect and reconnect using different terminal types, allowing applications to continue running without being aware of the change in terminals. ; Multiple windows: Multiple terminal sessions can be created, each of which usually runs a single application. The windows are numbered, and the user can use the keyboard to switch between them. Some GUI terminal emulators provide tabs or otherwise similar functionality to this. Each window has its own scroll-back buffer, so that output is captured even when the window isn't actively displayed, and that history can be saved even when migrating to another computer. Windows can be split-screened. While some text applications have this functionality built in, a terminal multiplexer allows any application to be split-screened alongside any number of other applications. ; Session Sharing: Terminal multiplexers allow multiple computers to connect to the same session at once, enabling collaboration between multiple users. The same computer can also be used to make multiple simultaneous connections, providing alternative functionality to screen-splitting, particularly for computers with multiple monitors.
GNU Screen: the prototypical terminal multiplexer, first released in 1987
mtm: billed as "perhaps the smallest useful terminal multiplexer in the world"
neercs: is a GNU screen workalike. It supports window thumbnailing and graphical animated screensavers. It also supports 3D console switching via the libcaca ASCII art library.
splitvt: split terminal utility.
TD/SMP: introduced by DEC on their VT330/340 terminals, TD/SMP was proprietary and only widely supported by their own terminal servers
tmux: A modern GNU Screen workalike, released in 2007; it is BSD-licensed, allows multiple panes, and has a scriptable command interface. tmux aimed to allow the sharing of a single window between multiple terminals, while keeping the other windows in the same session entirely separate. tmux has been part of the OpenBSD base system since 2009's version 4.6.
Twin : a full-fledged window manager for text windows. Initially started as an MS-DOS project, it was later ported to Linux.
