Tasmota is an Open Source firmware originally developed to hack modules from the Chinese manufacturer Itead Sonoff since 2016 by Theo Arendst. Its goal was to provide Sonoff ITEAD devices based on ESP8266 / ESP8285 with MQTT firmware that can be updated wirelessly (Over the Air or OTA) using the Arduino IDE. Since then, the firmware has evolved and supports other home automation modules based on ESP8285, ESP8266. The ESP32 version is under development. A very complete documentation is available on GitHub.