I suppose this stops working if you SSH into some box and run tmux there? I've implemented something similar, but as an urxvt plugin instead, which avoids that limitation: http://www.cs.helsinki.fi/u/tmtynkky/urxvt.png (Once Alt-O is pressed, the hotkeys with the red background appear next to each link; pressing the hotkey opens the link in browser and copying to clipboard is also possible)