It’s a small vending machine on the internet where people anonymously send a friend three postcards, one word at a time. The first two cards are unsigned, and the last one reveals who sent them. It’s meant to be a slow, kind surprise in the mail.
I shared this on HN a while back, and it gave us a quiet little push. Since then, we’ve sent 246 out of the 300 postcards we set out to deliver this year. Things have slowed down lately, but the whole thing is automated, costs almost nothing to run, and has been a lot of fun to work on!