I got intrigued with "early internet" style websites and found: https://nightfall.city/classifieds/, a service that lets people send messages to a webserver using netcat, so I remade that same service using two bash scripts, and am currently hosting a demo at:https://message.alessandroferrari.live/
I also made a Docker image for people to run this service on their own: https://github.com/Ferryistaken/messageboard
You can send messages on my board by running:
nc serveo.net 1915
ave
<message>
.