I would like to have better tools for annotating code with its relationships to legal text that it models. I don't need there to be a visual line (though it might not hurt), but I do need a convenient way to create an "annotation" which includes disjoint segments of text, where annotations can overlap one another, and can be linked from symbols in the code, so that when I mouse-over the relevant code, the linked sections of text are highlighted, or something. There's a lot of room to improve the way code and text relate to each other. If you could even implement something like that inside Jupyter I think it would be illustrative.