From the site's description:
The idea behind this event is to promote Web Standards. Plain and simple. This includes proper use of HTML, semantic markup, a good hierarchy structure, and of course, a good old play on words. It's time to show off your
<body>for what it really is.
This site is built using React and Gatsby - but that doesn't mean it isn't build using solid and accessible markup!
For future reference, here's a screenshot of the site in it's naked form: