Show HN: Learn React and D3 in the browser with runnable code playgrounds

I agree

I'm afraid that's not how Show HN works. Many, if not most, of the projects on Show HN are commercial projects--commercial projects are just fine. In addition, Swizec is a long-time, productive HNer and has written a number of free educational blog posts on d3 and/or React and dataviz.

So even though I'm not particularly interested in the product (looks like a good class, but I already know React and d3 quite well), I'm upvoting to counter any of your downvotes.