Earlier quoted context omitted.
Honestly, it would be odd for a tmux article to go without mentioning screen but there is nothing odd about a screen article not mentioning tmux. Speaking of which, I would like to see an article on tmux. Every now and then a screen article pops up and a few people chime in with the vague advantages of the BSD-licensed tmux, but I haven't seen any actual articles on tmux.
I use both. The only big difference? Besides the license? Screen uses 'Ctrl+A' while tmux uses 'Ctrl+B' and screen -r (to reattach) is replaced by tmux attach. That's it, for me at least. tmux seems to have a lot more features, but I only use 10% of them.
From what I can tell, screen has better handling of colors. tmux seems to mess up the [90m; -like sequence for colors 8-15.
Also, I like the ability to highlight screen's current screen with colored parentheses.