Stimulus (by Basecamp) is a modest JavaScript framework for the HTML you already have.
This demo was made to show Stimulus-based controllers, actions and targets. As a proof of concept it implements a rough controller which places server-side rendered markup into DOM. Think of Stimulus without the need of Turbolinks. As a result this demo feels like a single-page application (SPA) even though it is in fact kind of a multi page application (MPA).
Hope it's useful!
https://stimulusjs.demo.tebe.ch
Run the demo by starting your favorite webserver in your project folder.
# Start the built-in PHP server
$ php -S localhost:9999
Then, open http://localhost:9999 in your browser.