That was the first public release. There used to be a History.md file in the repo with the January date. There was a lot of experimentation even before that - b

That was the first public release. There used to be a History.md file in the repo with the January date. There was a lot of experimentation even before that - browsers started adding experimental WS support on the second half of 2009, right as node was gearing up. Some artifacts from that era: https://github.com/socketio/socket.io/blob/5518f8cb2c41251282e863a5a43f2194f6b0299f/History.md https://github.com/socketio/socket.io/blob/5518f8cb2c4125128... https://robots.thoughtbot.com/real-time-online-activity-monitor-example-with-node-js-and-websocket https://robots.thoughtbot.com/real-time-online-activity-moni... https://groups.google.com/d/msg/nodejs/1Bla2JHc3f0/N3fpKe7dYWYJ https://groups.google.com/d/msg/nodejs/1Bla2JHc3f0/N3fpKe7dY... Another thing to keep in mind is that the precursor SSJS environments like Jack/Narwhal, Helma etc probably added it even earlier. Hard to tell since GitHub itself was new and many of these sources are hard to find today.