Hi,

DOjS
I recently release V0.96 of DOjS. DOjS is a JavaScript engine aimed at creative coding and creating games.
DOjS provides a JavaScript-able canvas with WAV and MIDI sound support for systems running MS-DOS, FreeDOS or any DOS based Windows (like 95, 98, ME).
It features a native API as well as a p5js compatibility layer on top of that.
DOjS comes with a detailed API documentation as well as a bunch of examples.
https://github.com/SuperIlu/DOjS

jSH
Also, there is the more recent sister project jSH which provides an API to create text mode user interfaces (TUIs) and is more focused on scripting common DOS tasks like file renaming, text parsing/conversion, etc.
https://github.com/SuperIlu/jSH

Binary and source downloads are available for both projects on the GitHub pages.

Regards
Ilu