They have the software on Github and the hardware layouts (as well as additional things like Fritzing files for some boards) available through their documentati

They have the software on Github and the hardware layouts (as well as additional things like Fritzing files for some boards) available through their documentation - e.g.: - Arduino Uno: https://docs.arduino.cc/hardware/uno-rev3#resources https://docs.arduino.cc/hardware/uno-rev3#resources - Arduino Nano 33 IoT: https://docs.arduino.cc/hardware/nano-33-iot#resources https://docs.arduino.cc/hardware/nano-33-iot#resources