This is "Open Hardware" which usually means open PCB or chip schematics, so people can modify or extend the board. OpenWRT is "Open Software that runs on closed hardware".
After checking a couple, Kind of seems like a lot of boards on this "open hardware" list might not actually be open hardware?
https://templates.blakadder.com/ has almost 3,000 devices flashable onto Tasmota firmware.
For older Tuya devices there's https://github.com/tuya-cloudcutter/tuya-cloudcutter
OpenBeken https://github.com/openshwprojects/OpenBK7231T_App covers 800 of the newer generation Tuya devices.
And there's a large community adapting ESP32 devices onto https://esphome.io/
After checking a couple, Kind of seems like a lot of boards on this "open hardware" list might not actually be open hardware?
Here's an example of what open hardware is supposed to be: https://github.com/greatscottgadgets/ubertooth/tree/master/h...