If we are going to broaden this to Screen and its "TUI" style features, then the most complete effort at a programmable TUI in the Linux space I've seen is `desktop-tui`.

https://github.com/Julien-cpsn/desktop-tui

It is incomplete but takes what is almost a side aspect of TWIN and runs with it.

https://github.com/cosmos72/twin

TWIN is nearly 20 now and does quite a lot. It even has a Wikipedia page.

https://en.wikipedia.org/wiki/Twin_(windowing_system)

It runs on lots more OSes than just Linux.

I ment programs that implement persistent (shell) sessions.