> With this both share he same view but can move cursors independently.
Does this mean they have 2 separate cursors, or that that can control the same cursor? Your can sort of do the same thing in screen by using a nested screen session and sharing the outer session with the other user.
Even better than raw tmux is using tmate. I fumbled with tmux sessions and permissions for awhile but tmate makes it trivial. It's a free service but it really seems like they're leaving money on the table (I'd pay for it, anyway).
If Alice has a session on a remote machine you have access to. You can run `tmux new-session -s bob -t Alice`
With this both share he same view but can move cursors independently.