The history of real-time text probably goes back to at least the 1960's on the Compatible Time-Sharing System (CTSS). https://en.wikipedia.org/wiki/Talk_(softw

The history of real-time text probably goes back to at least the 1960's on the Compatible Time-Sharing System (CTSS). https://en.wikipedia.org/wiki/Talk_(software) https://en.wikipedia.org/wiki/Talk_(software) if you're on macOS, you have this command installed http://mailman.postel.org/pipermail/internet-history/2002-December/000195.html http://mailman.postel.org/pipermail/internet-history/2002-De... (click on "Previous message" a few times too) https://en.wikipedia.org/wiki/Real-time_text https://en.wikipedia.org/wiki/Real-time_text