That sounds like a nice way to do it, too. I heard about it before, but don't know R, so I didn't really consider it.

The reason I chose lmt is that it correctly keeps the markdown language syntax of the code blocks. That means I can put my literate config into my Zettelkasten [1] or [2] and watch it pretty-print in the browser.

There are also literate [3] and org-babel [4], but I don't think they are future proof. .lit is a random format and .org basically requires Emacs+orgmode.

1: https://github.com/srid/emanote

2: https://wiki.dendron.so/

3: https://github.com/zyedidia/Literate

4: https://orgmode.org/worg/org-contrib/babel/intro.html

Do these things work with any programming language? Like, do they still allow for "squiggly lines" (linter/static typing) in the editor?

For lmt/markdown: I believe yes, to the extend the editor allows for it. It is seemingly just like regular mardkown code blocks. I get the correct syntax high-light in the ``` code blocks. I don't have lint/LSP setup yet (currently moving to Neovim), so I can't say anything about that.

Literate/.lit: I don't know, I guess not.

Emacs/orgmode: Yes, this also does syntax highlight. And you can edit the code-block in a separate window as if it was a "real" source code file. I've been using this for almost two years now. Personal opinion: I don't think the benefits of Emacs outweight the cons.