tmux is a "terminal multiplexer". It allows a number of terminals (or windows) to be accessed and controlled from a single terminal. It is intended to be a simple, modern, BSD-licensed alternative to programs such as GNU screen.
License: BSD License (revised)
Changes:
Support for windows remaining open after process inside dies. A command prompt and window index prompt. The ability to bind alt (meta) keys. Next word and previous word keys in copy mode. The ability to set window titles in xterm. A revamped paste buffer system. A scroll status line to show the current window. A number of bugfixes and minor feature additions.
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