Disagree about processing. Agree about standards. The Arduino's standard for i/o headers, its development library for avr libc and avr-gcc, and its usb->serial

Disagree about processing. Agree about standards. The Arduino's standard for i/o headers, its development library for avr libc and avr-gcc, and its usb->serial interface for pushing hex files ("sketches") into the chip are where it shines. It's not a "printf" but rather an S100 bus if you will.