r/tmux

tmux - an awesome alternative to screen

tmux is a terminal multiplexer: it enables a number of terminals (or windows), each running a separate program, to be created, accessed, and controlled from a single screen. tmux may be detached from a screen and continue running in the background, then later reattached. https://tmux.github.io

r/tmux is a SFW subreddit with 26 thousand subscribers, created in 2011.