Bifrost: Simple and fast websocket server

https://github.com/alternatelabs/bifrost

Bifröst is a standalone websocket server written in Crystal. It’s easy to use and works with any server side language that can use JSON Web Tokens.

Why use Bifröst?

Tools like ActionCable seamlessly integrate websockets into your web framework but can put stress on your web servers and consume a lot of memory, making your application harder to deploy and scale.

Crystal delivers blazing fast performance with minimal memory footprint so Bifröst can handle thousands of websocket connections on a tiny VPS or hobby dyno on heroku.