Simon Willison’s Weblog

7 items tagged “websockets”

How Zoom’s web client avoids using WebRTC (via) It turns out video conferencing app Zoom uses their own WebAssembly compiled video and audio codecs and transmits H264 over WebSockets. # 18th April 2019, 6:20 pm

websocketd (via) Delightfully clever piece of design: “It’s like CGI, twenty years later, for WebSockets”. Simply run “websocketd --port=8080 my-program” and it will start up a WebSocket server on port 8080 and fire up a new process running your script every time it sees a new WebSocket connection. Standard in and standard out are automatically hooked up to the socket connection. Since it spawns a new process per connection this won’t work well with thousands of connections but for smaller scale projects it’s an excellent addition to the toolbok—and since it’s written in Go there are pre-compiled binaries available for almost everything. # 26th January 2019, 2:38 am

Live htop. Neat, simplest-thing-that-could-possibly-work implementation of a tool that continually pipes the output of the htop command to a browser over a WebSocket. The scripts loops every 2 seconds, runs htop, pipes it through a utility to convert the output to HTML and writes that to a file. Then the server.js Node.js script watches for changes to that file and pipes the entire file contents to the browser via The index.html page in the browser subscribes to the WebSocket and updates the entire page using innerHTML every time it receives an event. # 1st November 2017, 6:07 pm

What’s the cheapest or free stack solution to deploy and experiment with a realtime application in 2016?

Heroku have a good free tier, and comprehensive support for deploying both Python and Node.js. If you are mainly interested in realtime I would suggest starting out with Node.js on Heroku. Depending on the complexity of your project you might even be able to use raw Node.js without adding something like Express.

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What are the differences between node.js and websockets?

This is like asking “what’s the difference between PHP and HTTP”. Node.js is a technology framework you write code in. WebSockets is a protocol which can be implemented using a technology framework. You can use Node.js to implement the server-side aspect of WebSockets.

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Web Sockets in Tornado. Bret Taylor has a simple class making it trivial to experiment with the Web Sockets protocol (now shipping in Chrome) using the scalable Tornado application server. He also raises the million dollar question: what will existing load balancers and proxies make of the new protocol? # 31st December 2009, 11:54 am

Real time online activity monitor example with node.js and WebSocket. A neat exploration of Node.js—first hooking a “tail -f” process up to an HTTP push stream, then combining that with HTML 5 WebSockets to achieve reliable streaming. # 8th December 2009, 11:07 pm