Goodbye

[richard]

It's not running an interpreter but compiled/assembled code from the Arduino IDE (which I believe is built upon the gcc compiler). You can download the bootloader and flash it into a blank microcontroller using a device programmer (which can actually be another Arduino) and it "becomes" an Arduino.

that's pretty right but if you step away from the Arduino standards things get interesting.
I made a prototype pid based damper controller to regulate room temp on woodheaters all good on Arduino board uno atmega328 . for production I thought I would power it from 3.3v and use int osc to save components . turns out atmega328 won't run at 16mhz at that voltage had to drop back to 8mhz . then the boot loader needs to be replaced
. then could not get reliable loads using int osc , so I had to buy a programmer . then I thought what am I gaining over the pic environment , exactly nothing
xc8 and mcc is just lovely
ps. nearly forgot
when the load fails some times the config fuses get corrupted and the chips have to reprogrammed with a hv programmer they cannot be flashed by an other Arduino
I binned a few till I discovered that little gem

[HenrikOlsson]

Not just any AVR MCU you like I think. Only those supported.

Yes, of course. I didn't mean it could be any 8-bit ATMEL just that the original Arduino is based on an 8-bit ATMEL processor. Obviously you need to use a microcontroller for which support exists in the Arduino environment. The cool thing of course is that "anyone" can add support for devices to the environment which I believe is why you now can program the ESP8266 directly from the Arduino IDE.

I've not used an Arduino for anything. All I've ever done with the IDE is flashing an Openlog blackbox with its firmware.

Of course there are limitation, problems, issues and bugs - as is always the case :-)