Basically a duplicate of https://news.ycombinator.com/item?id=23731712, also on the front page at the moment.

This is cool. I understand the reason behind the unusual licensing, but I don’t love it. Anybody tried this out?

I haven't, but I'm will. In the meantime, most of the chatter is on https://maxxinteractive.com/books/misc/page/not-just-a-theme.

I expected the main page (this) would be better, but I was wrong.