Modern UTF-8 encoding and present day tools makes it relatively easy to make many codepoints work relatively better even on DOS, thanks to readily available bitmap fonts.
Here's some code that's easy for a lot of people to play with, especially if you are looking to have it running on your firmware / other embedded projects.
Of course, you can use pretty much any OS as a bootstrap loader for pretty much anything. There has been a loadlin.exe for example, it would load and run a Linux kernel. A gratis variant of BeOS also loaded from DOS iirc.
Interesting. I wonder how memory is handled due to the # of potential characters in UTF-8, or maybe only a subset of characters are allowed. Or is there a TSR handling that from a database on disk.
I cannot get to the twitter site and xcancel just loops so I could n0t see the post.
Within one segment of 64kB, you could load 8 or so blocks; You should be able to do 1 major CJK language overall (with 20-30 blocks) and Latin together and leave the rest of the memory for other things;
So you can make a proper application/browser with fonts compiled right into the core.