What I really liked about matlab was that you could programmatically generate figures and then modify them, by adding annotations etc. This seems like a logical thing for plotly or vega or one of the javascript python image libraries to add.

That said, I would not pay for this. Python has an awesome free and open source ecosystem, I cant imagine using pytorch, scikit learn, numpy, pandas etc for free then paying to annotate my plots.

I understand. I intended to charge for certain usage types only. MPLG will very likely be free for individuals, but you can buy a license to unlock the following (individually):

- educational features such as tooltips and explanations for common python and matplotlib functions;

- commercial use;

- educational use (as part of a curriculum).

- potentially, export to other languages (Julia).

You can do that with ROOT aswell.