htmx allows you to access AJAX, WebSockets and Server Sent Events directly in HTML, using attributes, so you can build modern user interfaces with the simplicity and power of hypertext.

htmx is small (~7kb gzipped), dependency-free, and even IE11 compatible. It’s the successor to intercooler.js and even comes bundled with a very nice haiku:

javascript fatigue:
longing for a hypertext
already in hand