Fundamentally they do the same thing. TMUX has a nice status bar, it's easier to play around with windows and it's got 256 colours support, as far as I'm aware.

Fundamentally they do the same thing. TMUX has a nice status bar, it's easier to play around with windows and it's got 256 colours support, as far as I'm aware. But really the difference is in TMUX having a dedicated community while GNU screen is just another GNU utility.