Hyperapp is an ultra lightweight (1kb), minimal, functional, javascript library for building UIs. It comes with a VDOM engine and state management without any dependencies. In this lesson, we build a simple counter app. We include the Hyperapp library using the Unpkg link: https://unpkg.com/hyperapp and then attach it to our page on the window.main global.
To build a counter, we only need to add a bit of state and a couple actions to our application to get it to work.