ARDUINO NANO is a small, complete, breadboard-friendly board based on the ATmega328 (Arduino Nano 3.x). It has pretty much the same functionality as the Arduino Duemilanove, but in a different package. It only lacks a DC power jack and works with a Mini-B USB cable instead of a standard one.
If you are interested in boards with similar functionality, on Arduino you can find:
Arduino NANO 33 BLE
Arduino NANO 33 BLE SENSE
Arduino NANO 33 IoT
Arduino Micro
