Zellij

Scrolling

Zellij support scrolling with mouse out of the box, and can auto-detect a scrollable program and switch from scrollback buffer to it.

Zellij is slow at displaying ANSI-colored content over a slow SSH connection with buffer scrolling involved.
1. Zellij is fast too if no scrolling is involved, e.g. colored content is less than tput lines and buffer is clear.
2. Tmux is fast in both cases.
3. Zellij updates SCROLL: 0/xxx after each line of output, which probably slowed it down.
Zellij reports Sixel support in Primary Device Attributes (DA1) response even if underlying terminal does not support it. https://github.com/zellij-org/zellij/issues/3158