Instead of finding a more descriptive name or adding a short description below, they put it on a completely different site.
But I'm a bit of a contrarian and every time someone tells me to drop IE support I think "Maybe I won't."
Still, there's a pretty steep curve to developing them, and that generally translates into a shorter lifetime unless they take off in popularity. For example, tooling support, for things like autocomplete, highlighting, debugging will need to be implemented. There's also a lack of community answering questions, making it difficult to pick up for beginners (no stack overflow, etc).
I realize this sounds harsh but truthfully, it made me immediately disregard the library. If this is how you would solve these issues in JavaScript I'm not taking you seriously.
The web API offers an elegant separation of content, style and logic and these examples are just stuffing everything into logic. Don't do this
Separation of HTML/CSS/JS doesn't always mean separation of concerns. Every application has a different definition of a "concern", and if it doesn't align with the separation between languages, you don't get decoupled code, you intensify the symptoms of tight coupling.
"Focus on the fundamentals of HTML, CSS and JS. Everything else is ephemeral."
I don't mean to pick on whomever wrote these examples, but the ~7 lines of JS for the first example (fading out) shows either a lack of basic understanding or intentional complication to make hyperscript appear better in comparison. A more reasonable solution is 3 lines of code.