is-land using 
Preact
Scroll down
Client-rendered Preact
Example from https://preactjs.com/guide/v10/getting-started#no-build-tools-route
Server-rendered Preact (SSR)
No hydration, HTML only
Without hydration, the island is unnecessary.
Hello from Preact!
With Hydration
Auto-init
Counter: 0
Manual init
Counter: 0