Any Markdown implementation which allows for custom directives and is CommonMark-compliant is good enough for me. MyST, for example, lets you do :::{makeu

Any Markdown implementation which allows for custom directives and is CommonMark-compliant is good enough for me. MyST, for example, lets you do :::{makeup-highlight} :lang: elixir defmodule A do def b, do: :ok end ::: :::{pygments-highlight} :lang: python class B: pass ::: Since MyST has intermediaries that just give you an AST, you have a lot more extensibility using directives and roles to do special things (including includes). You can of course just use MyST proper, but getting to transform the AST myself how I see fit is a big win in my eyes. Pandoc does have AST and all that too, but MyST's implementation strikes the best balance for me.