OP's linked to the relay board carrier Olimex makes but that is not really the right one, they probably meant to link this: https://www.olimex.com/Products/IoT

OP's linked to the relay board carrier Olimex makes but that is not really the right one, they probably meant to link this: https://www.olimex.com/Products/IoT/ESP8266/MOD-WIFI-ESP8266-DEV/open-source-hardware https://www.olimex.com/Products/IoT/ESP8266/MOD-WIFI-ESP8266... It's an open source hardware ESP8266 module by Olimex, roughly comparable to modules like the ESP-12. The ESP8266 chip itself is obviously not open source but the module surrounding it is. But yeah I agree, these are pretty meh... I've actually used one of these Olimex modules and there's nothing special about them. IMO, being OSH doesn't really do all that much for you in this case, especially when the actual chip isn't also OSH, and these modules don't even have FCC pre-cert. They've also been around for a long time, from what I remember they were one of the earliest crop of modules with most/all of the pins of the ESP8266 broken out that became available.