I am a big believer in Literate Programming, and for a long while, the most expedient way for me to do it was to just use a .dtx (documented TeX file), since it allowed me to work with a straight-forward toolchain (a TeX editor/previewer such as TeXshop or TeXworks) --- adding Peter Wilson's docmfp package (https://ctan.org/pkg/docmfp) made it general-purpose enough for my needs, but I didn't like the sea of grey of the entire document being a comment in the editor.

I looked around and considered other tools, and Quarto was in the running, but it didn't seem straight-forward to get it to support multiple languages (my current project began in OpenSCAD, migrated to Python, and still maintains an OpenSCAD wrapper, as well as needing to write out G-code and DXFs).

Wound up asking how to do this w/ LuaLaTeX and got a very helpful answer:

https://tex.stackexchange.com/questions/722886/how-to-write-...

which I used to create a package which suits my needs, despite some serious drawbacks/failings (the .sty file _and_ .tex file have to be edited when a new file is added (or an old one removed), line numbering has to be managed manually, and I haven't puzzled out a seamless way to manage the Markdown file for readme.md).

Curious what other folks use/how they approach this sort of thing, so glad of this thread.