Microcontrollers existed before the Arduino ... Basic Stamp is stored in 256 bytes of the EEPROM. This code is read by a PBASIC interpreter on the PIC, dutifully following commands to blink a LED ...

This isn’t an ESP8266 shield, either: you can write code for the ESP module, connect the serial pins, and hit the program button. The basic functions of the Arduino IDE – pinMode, digitalRead ...