Question: I am interested to know if anyone has built a javascript websocket listener for a browser. Basically the server side of a websocket that runs in a client. This would allow messages to be sent to the client directly. Why? Because instead of having a Node.js, python, java, etc, server process sitting on or near the client/browser, I can just use a thread in the browser as a listening server thread. I don't think that any browsers support this currently.

I've run across answers like this: <https://news.ycombinator.com/item?id=2316132>

Just curious if anyone has done this. I believe that the current Websockets spec does not support listeners on the browser. It would make the deployment of various peer-to-peer applications a bit easier to deploy.

Answer: 
[WebRTC](https://webrtc.org/getting-started/overview) allows for peer-to-peer connections to be made between browsers. 

You would still need a server in order for individual users to discover each other but then they could connect directly to each other rather than having to pass all their traffic via a central server.
The idea.

You can use a simple **echo server** written in any language. Your script can send the data to the server then get it back, handle it on the same page with different functions/classes emulating the real server.

An example: <http://www.websocket.org/echo.html>

Then, you can think about different formats of packets to/from server to diffirentiate them inside one script.