Socket.IO is JavaScript library for realtime web applications. It utilises websocket technology maintain two-way real time communication channel between web browser and web server.

Thanks to websockets we can make single page applications – without save buttons, page loads or waiting. Whenever user makes change in application, for example writes a message, changes his settings, uploads a picture, we can watch this changes and respond to them.

It works on every platform, browser or device, focusing equally, reliability and speed.