[Per_Bothner]

I am working on a re-write (https://github.com/xtermjs/xterm.js/issues/4800) of the xterm.js "BufferLine" data structures that (among other benefits) could potentially support variable-width fonts in the terminal. Instead of a 2-dimensional grid of character cells, the primary data structure will be a list of logical lines, each consisting of characters and attributes.

A rather modest enhancement to the vt100/xterm escape sequences would be a mode where screen addressing would be in terms of logical characters and logical lines. The application should not need to know the width of characters or how lines are broken into screen rows. This makes use of variable-width fonts practical - which is necessary for decent rendering of many scripts.

DomTerm's display engine (https://domterm.org) does support lines containing a mix of monospace and variable width characters, and know how to wrap such lines. I'm working on long-term replacing DomTerm's native display engine with xterm.js (for speed and other reasons) which requires making xterm.js more versatile.