Anyway.
Paco Grug talks about how they want a website (e.g. a blog) without a server-side build-step. Just data, shape of data, and the building happening automagically, this time on the client. HTML has javascript and frames for that, but HTML painfully lacks transclusion, for header menu, sidebar and footer, which birthed myriads of web servers and webserver technologies.
It seems that .xml can do it too, e.g. transclusion and probably more. The repo doesn't really showcase it.
Anyway, I downloaded the repo, and ran it on a local webserver, it works. It also works javascript disabled, on an old browser. (Not as opened as a file tho.) Nice technology, maybe it is possible to use it for something useful (in a very specific niche). For most other things javascript/build-step/dynamic webserver is better.
Also, I think that for a blog you'll want the posts in separate files, and you can't just dump them in a folder and expect that the browser will find them. You'll need a webserver/build-step/javascript for that.