For those who are curious, the wifi board depicted in this project is the venerable ESP8266. It’s really been a hardware tinkerer’s dream to be able to add such a capable wifi radio to projects for so cheap ($2 on aliexpress if you don’t mind waiting 6 weeks for it to ship from China).
I got one of these for my kaypro 2'84, and it was simple to get working. I use it to transfer files from my modern laptop over the network via Kermit at a blistering 19.2kbaud
This looks handy, I've got a 3COM Etherlink III and mbrutmans TCP stack in my IBM PC but it rules out a lot of older software that doesn't know anything other than a modem.