The WebSocket API makes it possible to open a two-way interactive communication session between the user's browser and a server. With this API, you can send messages to a server and receive responses without having to poll the server for a reply.| MDN Web Docs
The EventSource interface is web content's interface to server-sent events.| MDN Web Docs
Cettia is a web framework, which consists of a JavaScript library that runs in the browser and on Node.js and a Java library for the back end.| golb.hplar.ch