The js via html tags is something I see also in Alpine.js, which has gotten a lot of press lately.

Is this an alternative, or is each really its own niche (and you might use both)? Is there a comparison?

Edit: It seems that htmx is almost entirely around AJAX, and Alpine around a) binding element data to objects and b) css & animations (such as hiding a popup). It would make a lot of sense to use them together (and the hx- even complements the x-). Is that correct?