Tree Walk Format (TWF) is a flat file format to describe your family tree. It allows you to describe your family tree in one (or more) files which are editable using your favorite text editor.
I see it as a viable alternative to GUIs such as Gramps or TUIs such as llines(Lifelines).
Currently it is Unix/Linux only since it uses groff/dot to generate the graph depicting the family tree. The git repo has a script that turns the flat file you created into a pdf depicting your family tree. I assume Windows users may be able to use it too using WSL.
It should be possible to generate an equivalent GEDCOM from the TWF input, but that is not implemented yet.
Some additional usage info including examples of family trees from the Bible which are denoted using the TWF format are available at: https://ces.mataroa.blog/blog/twf_ftwmd