You've obviously written this because screen wasn't doing the right thing, but your readme only explains that it's a "young project, not a drop-in GNU screen replacement". What are its advantages over screen or tmux?
screen actually works the same way architecturally: it parses all output through its own built-in terminal emulator and redraws from that state on reattach. But that emulator is decades old and lags far behind what modern programs emit. Whatever it doesn't understand gets dropped or mangled on redraw. boo swaps that layer for libghostty-vt, Ghostty's VT core, so the saved state matches what your terminal would actually display, and terminal queries get answered while detached so TUIs don't hang unattended.
tmux is great, it was just never the model I wanted. I really liked screen's simplicity, sessions and a prefix key and nothing else to learn, and boo keeps exactly that.
They also compose: a boo session is just a PTY running a program, so you can run tmux inside one if you want.
Of course, it's impossible to know for sure what was LLM processed or not, but some of your posts (like this one) are getting classified that way.
Screen is 1 server to 1 client.
In screen each client session is a fork of the screen server. In tmux there's one server and many client forks iirc.
Without -x though it works as originally described.
Edit: gnu screen 1.0 was originally released in 1987. The -x flag was released in screen 3.0 in the 90s. TIL